21444501455 has 32 divisors (see below), whose sum is σ = 28272416256. Its totient is φ = 15516993024.

The previous prime is 21444501451. The next prime is 21444501457. The reversal of 21444501455 is 55410544412.

It is not a de Polignac number, because 21444501455 - 2² = 21444501451 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444501451) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2969429 + ... + 2976641.

It is an arithmetic number, because the mean of its divisors is an integer number (883513008).

Almost surely, 2^21444501455 is an apocalyptic number.

21444501455 is a deficient number, since it is larger than the sum of its proper divisors (6827914801).

21444501455 is a wasteful number, since it uses less digits than its factorization.

21444501455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8147.

The product of its (nonzero) digits is 64000, while the sum is 35.

The spelling of 21444501455 in words is "twenty-one billion, four hundred forty-four million, five hundred one thousand, four hundred fifty-five".