28761720 has 128 divisors (see below), whose sum is σ = 94348800. Its totient is φ = 6971904.

The previous prime is 28761709. The next prime is 28761731. The reversal of 28761720 is 2716782.

It is an interprime number because it is at equal distance from previous prime (28761709) and next prime (28761731).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 160591 + ... + 160769.

It is an arithmetic number, because the mean of its divisors is an integer number (737100).

Almost surely, 2^28761720 is an apocalyptic number.

28761720 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 28761720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47174400).

28761720 is an abundant number, since it is smaller than the sum of its proper divisors (65587080).

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

28761720 is a wasteful number, since it uses less digits than its factorization.

28761720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309 (or 305 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 33.

The square root of 28761720 is about 5362.9954316594. The cubic root of 28761720 is about 306.3879056824.

The spelling of 28761720 in words is "twenty-eight million, seven hundred sixty-one thousand, seven hundred twenty".