28040310 has 128 divisors (see below), whose sum is σ = 81648000. Its totient is φ = 6819840.

The previous prime is 28040279. The next prime is 28040323. The reversal of 28040310 is 1304082.

It is a happy number.

It is a super-2 number, since 2×28040310² = 1572517969792200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 188116 + ... + 188264.

It is an arithmetic number, because the mean of its divisors is an integer number (637875).

Almost surely, 2^28040310 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28040310, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40824000).

28040310 is an abundant number, since it is smaller than the sum of its proper divisors (53607690).

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

28040310 is a wasteful number, since it uses less digits than its factorization.

28040310 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223 (or 217 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 28040310 is about 5295.3101892146. The cubic root of 28040310 is about 303.8045474359.

Adding to 28040310 its reverse (1304082), we get a palindrome (29344392).

The spelling of 28040310 in words is "twenty-eight million, forty thousand, three hundred ten".