21655255454 has 16 divisors (see below), whose sum is σ = 37126146048. Its totient is φ = 9280111032.

The previous prime is 21655255441. The next prime is 21655255493. The reversal of 21655255454 is 45455255612.

It is a super-2 number, since 2×21655255454² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156467 + ... + 260369.

It is an arithmetic number, because the mean of its divisors is an integer number (2320384128).

Almost surely, 2^21655255454 is an apocalyptic number.

21655255454 is a deficient number, since it is larger than the sum of its proper divisors (15470890594).

21655255454 is a wasteful number, since it uses less digits than its factorization.

21655255454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118799.

The product of its digits is 1200000, while the sum is 44.

The spelling of 21655255454 in words is "twenty-one billion, six hundred fifty-five million, two hundred fifty-five thousand, four hundred fifty-four".