28861638025 has 24 divisors (see below), whose sum is σ = 39082659264. Its totient is φ = 20968382400.

The previous prime is 28861638017. The next prime is 28861638041. The reversal of 28861638025 is 52083616882.

It is not a de Polignac number, because 28861638025 - 2³ = 28861638017 is a prime.

It is a super-2 number, since 2×28861638025² (a number of 22 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (49) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 28861638025.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 211659 + ... + 320191.

It is an arithmetic number, because the mean of its divisors is an integer number (1628444136).

Almost surely, 2^28861638025 is an apocalyptic number.

28861638025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28861638025 is a deficient number, since it is larger than the sum of its proper divisors (10221021239).

28861638025 is a wasteful number, since it uses less digits than its factorization.

28861638025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109521 (or 109516 counting only the distinct ones).

The product of its (nonzero) digits is 1105920, while the sum is 49.

The spelling of 28861638025 in words is "twenty-eight billion, eight hundred sixty-one million, six hundred thirty-eight thousand, twenty-five".