28375837581 has 32 divisors (see below), whose sum is σ = 46630563840. Its totient is φ = 14946554304.

The previous prime is 28375837579. The next prime is 28375837601. The reversal of 28375837581 is 18573857382.

It is not a de Polignac number, because 28375837581 - 2¹ = 28375837579 is a prime.

It is a super-2 number, since 2×28375837581² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28375837531) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 124006 + ... + 268568.

It is an arithmetic number, because the mean of its divisors is an integer number (1457205120).

Almost surely, 2^28375837581 is an apocalyptic number.

28375837581 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

28375837581 is a deficient number, since it is larger than the sum of its proper divisors (18254726259).

28375837581 is a wasteful number, since it uses less digits than its factorization.

28375837581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145305.

The product of its digits is 11289600, while the sum is 57.

The spelling of 28375837581 in words is "twenty-eight billion, three hundred seventy-five million, eight hundred thirty-seven thousand, five hundred eighty-one".