21550010221531 has 4 divisors (see below), whose sum is σ = 23509102059864. Its totient is φ = 19590918383200.

The previous prime is 21550010221477. The next prime is 21550010221561. The reversal of 21550010221531 is 13512201005512.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21550010221531 - 2²⁵ = 21549976667099 is a prime.

It is a super-2 number, since 2×21550010221531² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21550010221531.

It is not an unprimeable number, because it can be changed into a prime (21550010221561) 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, 979545919150 + ... + 979545919171.

It is an arithmetic number, because the mean of its divisors is an integer number (5877275514966).

Almost surely, 2^{21550010221531} is an apocalyptic number.

21550010221531 is a deficient number, since it is larger than the sum of its proper divisors (1959091838333).

21550010221531 is a wasteful number, since it uses less digits than its factorization.

21550010221531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1959091838332.

The product of its (nonzero) digits is 3000, while the sum is 28.

The spelling of 21550010221531 in words is "twenty-one trillion, five hundred fifty billion, ten million, two hundred twenty-one thousand, five hundred thirty-one".