28309647400 has 24 divisors (see below), whose sum is σ = 65819930670. Its totient is φ = 11323858880.

The previous prime is 28309647383. The next prime is 28309647403. The reversal of 28309647400 is 474690382.

It can be written as a sum of positive squares in 3 ways, for example, as 19870285444 + 8439361956 = 140962^2 + 91866^2 .

It is a super-2 number, since 2×28309647400² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28309647403) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 70773919 + ... + 70774318.

Almost surely, 2^28309647400 is an apocalyptic number.

28309647400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28309647400 is an abundant number, since it is smaller than the sum of its proper divisors (37510283270).

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

28309647400 is a wasteful number, since it uses less digits than its factorization.

28309647400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141548253 (or 141548244 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 43.

The spelling of 28309647400 in words is "twenty-eight billion, three hundred nine million, six hundred forty-seven thousand, four hundred".