28156908428 has 24 divisors (see below), whose sum is σ = 53988851280. Its totient is φ = 12742701120.

The previous prime is 28156908421. The next prime is 28156908457. The reversal of 28156908428 is 82480965182.

It is a super-2 number, since 2×28156908428² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 28156908428.

It is not an unprimeable number, because it can be changed into a prime (28156908421) 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, 1387151 + ... + 1407302.

It is an arithmetic number, because the mean of its divisors is an integer number (2249535470).

Almost surely, 2^28156908428 is an apocalyptic number.

It is an amenable number.

28156908428 is a deficient number, since it is larger than the sum of its proper divisors (25831942852).

28156908428 is a wasteful number, since it uses less digits than its factorization.

28156908428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2794697 (or 2794695 counting only the distinct ones).

The product of its (nonzero) digits is 2211840, while the sum is 53.

The spelling of 28156908428 in words is "twenty-eight billion, one hundred fifty-six million, nine hundred eight thousand, four hundred twenty-eight".