21655044166431 has 8 divisors (see below), whose sum is σ = 31094422392880. Its totient is φ = 13326181025472.

The previous prime is 21655044166423. The next prime is 21655044166433. The reversal of 21655044166431 is 13466144055612.

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

It is not a de Polignac number, because 21655044166431 - 2³ = 21655044166423 is a prime.

It is a super-2 number, since 2×21655044166431² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21655044166433) 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, 277628771326 + ... + 277628771403.

It is an arithmetic number, because the mean of its divisors is an integer number (3886802799110).

Almost surely, 2^{21655044166431} is an apocalyptic number.

21655044166431 is a deficient number, since it is larger than the sum of its proper divisors (9439378226449).

21655044166431 is a wasteful number, since it uses less digits than its factorization.

21655044166431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 555257542745.

The product of its (nonzero) digits is 2073600, while the sum is 48.

The spelling of 21655044166431 in words is "twenty-one trillion, six hundred fifty-five billion, forty-four million, one hundred sixty-six thousand, four hundred thirty-one".