28694666025 has 81 divisors (see below), whose sum is σ = 53836717207. Its totient is φ = 14608624800.

The previous prime is 28694665943. The next prime is 28694666057. The reversal of 28694666025 is 52066649682.

It is a happy number.

The square root of 28694666025 is 169395.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 10330079769 + 18364586256 = 101637^2 + 135516^2 .

It is not a de Polignac number, because 28694666025 - 2⁷ = 28694665897 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 58441030 + ... + 58441520.

Almost surely, 2^28694666025 is an apocalyptic number.

28694666025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28694666025 is the 169395-th square number.

28694666025 is the 84698-th centered octagonal number.

It is an amenable number.

28694666025 is a deficient number, since it is larger than the sum of its proper divisors (25142051182).

28694666025 is an equidigital number, since it uses as much as digits as its factorization.

28694666025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1044 (or 522 counting only the distinct ones).

The product of its (nonzero) digits is 7464960, while the sum is 54.

The spelling of 28694666025 in words is "twenty-eight billion, six hundred ninety-four million, six hundred sixty-six thousand, twenty-five".