21255355023454 has 4 divisors (see below), whose sum is σ = 31883032535184. Its totient is φ = 10627677511726.

The previous prime is 21255355023451. The next prime is 21255355023479. The reversal of 21255355023454 is 45432055355212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255355023451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5313838755862 + ... + 5313838755865.

It is an arithmetic number, because the mean of its divisors is an integer number (7970758133796).

Almost surely, 2^{21255355023454} is an apocalyptic number.

21255355023454 is a deficient number, since it is larger than the sum of its proper divisors (10627677511730).

21255355023454 is a wasteful number, since it uses less digits than its factorization.

21255355023454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10627677511729.

The product of its (nonzero) digits is 3600000, while the sum is 46.

The spelling of 21255355023454 in words is "twenty-one trillion, two hundred fifty-five billion, three hundred fifty-five million, twenty-three thousand, four hundred fifty-four".