28056123657 has 24 divisors (see below), whose sum is σ = 43382160640. Its totient is φ = 18100720080.

The previous prime is 28056123643. The next prime is 28056123671. The reversal of 28056123657 is 75632165082.

28056123657 is a `hidden beast` number, since 2 + 8 + 0 + 561 + 2 + 36 + 57 = 666.

It is an interprime number because it is at equal distance from previous prime (28056123643) and next prime (28056123671).

It is not a de Polignac number, because 28056123657 - 2¹² = 28056119561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28056123637) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1854682 + ... + 1869747.

Almost surely, 2^28056123657 is an apocalyptic number.

28056123657 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

28056123657 is a deficient number, since it is larger than the sum of its proper divisors (15326036983).

28056123657 is an equidigital number, since it uses as much as digits as its factorization.

28056123657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3724475 (or 3724463 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 45.

The spelling of 28056123657 in words is "twenty-eight billion, fifty-six million, one hundred twenty-three thousand, six hundred fifty-seven".