83857000921 has 4 divisors (see below), whose sum is σ = 83857617844. Its totient is φ = 83856384000.

The previous prime is 83857000901. The next prime is 83857000961. The reversal of 83857000921 is 12900075838.

83857000921 = 204764² + 204765².

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 41928705225 + 41928295696 = 204765^2 + 204764^2 .

It is a cyclic number.

It is not a de Polignac number, because 83857000921 - 2¹³ = 83856992729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (83857000901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5160 + ... + 409561.

It is an arithmetic number, because the mean of its divisors is an integer number (20964404461).

Almost surely, 2^83857000921 is an apocalyptic number.

83857000921 is the 204765-th centered square number.

It is an amenable number.

83857000921 is a deficient number, since it is larger than the sum of its proper divisors (616923).

83857000921 is a wasteful number, since it uses less digits than its factorization.

83857000921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 616922.

The product of its (nonzero) digits is 120960, while the sum is 43.

The spelling of 83857000921 in words is "eighty-three billion, eight hundred fifty-seven million, nine hundred twenty-one", and thus it is an aban number.