28156578906 has 16 divisors (see below), whose sum is σ = 58254991200. Its totient is φ = 9061887408.

The previous prime is 28156578887. The next prime is 28156578929. The reversal of 28156578906 is 60987565182.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80909536 + ... + 80909883.

It is an arithmetic number, because the mean of its divisors is an integer number (3640936950).

Almost surely, 2^28156578906 is an apocalyptic number.

28156578906 is an abundant number, since it is smaller than the sum of its proper divisors (30098412294).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28156578906 is a wasteful number, since it uses less digits than its factorization.

28156578906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161819453.

The product of its (nonzero) digits is 7257600, while the sum is 57.

The spelling of 28156578906 in words is "twenty-eight billion, one hundred fifty-six million, five hundred seventy-eight thousand, nine hundred six".