21551046455 has 64 divisors (see below), whose sum is σ = 28592403840. Its totient is φ = 15581030400.

The previous prime is 21551046449. The next prime is 21551046469. The reversal of 21551046455 is 55464015512.

It is a de Polignac number, because none of the positive numbers 2^k-21551046455 is a prime.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 119066465 + ... + 119066645.

It is an arithmetic number, because the mean of its divisors is an integer number (446756310).

Almost surely, 2^21551046455 is an apocalyptic number.

21551046455 is a deficient number, since it is larger than the sum of its proper divisors (7041357385).

21551046455 is a wasteful number, since it uses less digits than its factorization.

21551046455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405 (or 371 counting only the distinct ones).

The product of its (nonzero) digits is 120000, while the sum is 38.

The spelling of 21551046455 in words is "twenty-one billion, five hundred fifty-one million, forty-six thousand, four hundred fifty-five".