21955152554 has 24 divisors (see below), whose sum is σ = 36190271340. Its totient is φ = 9975558656.

The previous prime is 21955152553. The next prime is 21955152589. The reversal of 21955152554 is 45525155912.

It can be written as a sum of positive squares in 6 ways, for example, as 21029350225 + 925802329 = 145015^2 + 30427^2 .

It is not an unprimeable number, because it can be changed into a prime (21955152553) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 638147 + ... + 671670.

Almost surely, 2^21955152554 is an apocalyptic number.

21955152554 is a deficient number, since it is larger than the sum of its proper divisors (14235118786).

21955152554 is a wasteful number, since it uses less digits than its factorization.

21955152554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1309882 (or 1309865 counting only the distinct ones).

The product of its digits is 450000, while the sum is 44.

The spelling of 21955152554 in words is "twenty-one billion, nine hundred fifty-five million, one hundred fifty-two thousand, five hundred fifty-four".