21660551120531 has 32 divisors (see below), whose sum is σ = 23928202690560. Its totient is φ = 19538715398400.

The previous prime is 21660551120431. The next prime is 21660551120539. The reversal of 21660551120531 is 13502115506612.

It is a cyclic number.

It is not a de Polignac number, because 21660551120531 - 2³⁴ = 21643371251347 is a prime.

It is a super-2 number, since 2×21660551120531² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21660551120539) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 24798785 + ... + 25657373.

It is an arithmetic number, because the mean of its divisors is an integer number (747756334080).

Almost surely, 2^{21660551120531} is an apocalyptic number.

21660551120531 is a deficient number, since it is larger than the sum of its proper divisors (2267651570029).

21660551120531 is a wasteful number, since it uses less digits than its factorization.

21660551120531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 859547.

The product of its (nonzero) digits is 54000, while the sum is 38.

The spelling of 21660551120531 in words is "twenty-one trillion, six hundred sixty billion, five hundred fifty-one million, one hundred twenty thousand, five hundred thirty-one".