28937340 has 72 divisors (see below), whose sum is σ = 88216128. Its totient is φ = 7678080.

The previous prime is 28937333. The next prime is 28937347. The reversal of 28937340 is 4373982.

28937340 is a `hidden beast` number, since 289 + 37 + 340 = 666.

It is an interprime number because it is at equal distance from previous prime (28937333) and next prime (28937347).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 28937295 and 28937304.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28937347) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 66925 + ... + 67355.

It is an arithmetic number, because the mean of its divisors is an integer number (1225224).

Almost surely, 2^28937340 is an apocalyptic number.

28937340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28937340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44108064).

28937340 is an abundant number, since it is smaller than the sum of its proper divisors (59278788).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28937340 is a wasteful number, since it uses less digits than its factorization.

28937340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 819 (or 814 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 36.

The square root of 28937340 is about 5379.3438261558. The cubic root of 28937340 is about 307.0102455670.

The spelling of 28937340 in words is "twenty-eight million, nine hundred thirty-seven thousand, three hundred forty".