21534002057 has 8 divisors (see below), whose sum is σ = 22530513984. Its totient is φ = 20542511088.

The previous prime is 21534001991. The next prime is 21534002059. The reversal of 21534002057 is 75020043512.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21534002057 - 2²⁸ = 21265566601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21534002059) 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, 1246463 + ... + 1263620.

It is an arithmetic number, because the mean of its divisors is an integer number (2816314248).

Almost surely, 2^21534002057 is an apocalyptic number.

It is an amenable number.

21534002057 is a deficient number, since it is larger than the sum of its proper divisors (996511927).

21534002057 is a wasteful number, since it uses less digits than its factorization.

21534002057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2510479.

The product of its (nonzero) digits is 8400, while the sum is 29.

Adding to 21534002057 its reverse (75020043512), we get a palindrome (96554045569).

The spelling of 21534002057 in words is "twenty-one billion, five hundred thirty-four million, two thousand, fifty-seven".