21739178522 has 8 divisors (see below), whose sum is σ = 32622424500. Its totient is φ = 10865037024.

The previous prime is 21739178521. The next prime is 21739178581. The reversal of 21739178522 is 22587193712.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 18826309681 + 2912868841 = 137209^2 + 53971^2 .

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

It is a super-2 number, since 2×21739178522² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21739178521) 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, 2270147 + ... + 2279702.

Almost surely, 2^21739178522 is an apocalyptic number.

21739178522 is a deficient number, since it is larger than the sum of its proper divisors (10883245978).

21739178522 is a wasteful number, since it uses less digits than its factorization.

21739178522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4552240.

The product of its digits is 423360, while the sum is 47.

The spelling of 21739178522 in words is "twenty-one billion, seven hundred thirty-nine million, one hundred seventy-eight thousand, five hundred twenty-two".