38999999021 has 4 divisors (see below), whose sum is σ = 39144980700. Its totient is φ = 38855017344.

The previous prime is 38999998997. The next prime is 38999999023. The reversal of 38999999021 is 12099999983.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13162972900 + 25837026121 = 114730^2 + 160739^2 .

It is a cyclic number.

It is not a de Polignac number, because 38999999021 - 2²² = 38995804717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (38999999023) 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, 72490436 + ... + 72490973.

It is an arithmetic number, because the mean of its divisors is an integer number (9786245175).

Almost surely, 2^38999999021 is an apocalyptic number.

It is an amenable number.

38999999021 is a deficient number, since it is larger than the sum of its proper divisors (144981679).

38999999021 is a wasteful number, since it uses less digits than its factorization.

38999999021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144981678.

The product of its (nonzero) digits is 25509168, while the sum is 68.

The spelling of 38999999021 in words is "thirty-eight billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, twenty-one".