28157709507 has 8 divisors (see below), whose sum is σ = 38103965376. Its totient is φ = 18491629992.

The previous prime is 28157709493. The next prime is 28157709521. The reversal of 28157709507 is 70590775182.

It is an interprime number because it is at equal distance from previous prime (28157709493) and next prime (28157709521).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28157709507 - 2⁴ = 28157709491 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28157709507.

It is not an unprimeable number, because it can be changed into a prime (28157709607) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70043853 + ... + 70044254.

It is an arithmetic number, because the mean of its divisors is an integer number (4762995672).

Almost surely, 2^28157709507 is an apocalyptic number.

28157709507 is a deficient number, since it is larger than the sum of its proper divisors (9946255869).

28157709507 is a wasteful number, since it uses less digits than its factorization.

28157709507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140088177.

The product of its (nonzero) digits is 1234800, while the sum is 51.

The spelling of 28157709507 in words is "twenty-eight billion, one hundred fifty-seven million, seven hundred nine thousand, five hundred seven".