28954765921 has 9 divisors (see below), whose sum is σ = 29110271281. Its totient is φ = 28800089572.

The previous prime is 28954765909. The next prime is 28954766021. The reversal of 28954765921 is 12956745982.

It is a happy number.

The square root of 28954765921 is 170161.

It is a perfect power (a square), and thus also a powerful number.

It is a de Polignac number, because none of the positive numbers 2^k-28954765921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28954765121) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 44752020 + ... + 44752666.

Almost surely, 2^28954765921 is an apocalyptic number.

28954765921 is the 170161-st square number.

28954765921 is the 85081-st centered octagonal number.

It is an amenable number.

28954765921 is a deficient number, since it is larger than the sum of its proper divisors (155505360).

28954765921 is an frugal number, since it uses more digits than its factorization.

28954765921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1820 (or 910 counting only the distinct ones).

The product of its digits is 10886400, while the sum is 58.

The spelling of 28954765921 in words is "twenty-eight billion, nine hundred fifty-four million, seven hundred sixty-five thousand, nine hundred twenty-one".