21115054254 has 32 divisors (see below), whose sum is σ = 49567389696. Its totient is φ = 5869821600.

The previous prime is 21115054249. The next prime is 21115054267. The reversal of 21115054254 is 45245051112.

It is a super-2 number, since 2×21115054254² (a number of 21 digits) contains 22 as substring.

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 15 ways as a sum of consecutive naturals, for example, 6792222 + ... + 6795329.

It is an arithmetic number, because the mean of its divisors is an integer number (1548980928).

Almost surely, 2^21115054254 is an apocalyptic number.

21115054254 is an abundant number, since it is smaller than the sum of its proper divisors (28452335442).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21115054254 is a wasteful number, since it uses less digits than its factorization.

21115054254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13587600.

The product of its (nonzero) digits is 8000, while the sum is 30.

The spelling of 21115054254 in words is "twenty-one billion, one hundred fifteen million, fifty-four thousand, two hundred fifty-four".