21115020054 has 16 divisors (see below), whose sum is σ = 43212134592. Its totient is φ = 6874657608.

The previous prime is 21115020019. The next prime is 21115020067. The reversal of 21115020054 is 45002051112.

It is a self number, because there is not a number n which added to its sum of digits gives 21115020054.

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, 40920324 + ... + 40920839.

It is an arithmetic number, because the mean of its divisors is an integer number (2700758412).

Almost surely, 2^21115020054 is an apocalyptic number.

21115020054 is an abundant number, since it is smaller than the sum of its proper divisors (22097114538).

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

21115020054 is a wasteful number, since it uses less digits than its factorization.

21115020054 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81841211.

The product of its (nonzero) digits is 400, while the sum is 21.

Adding to 21115020054 its reverse (45002051112), we get a palindrome (66117071166).

The spelling of 21115020054 in words is "twenty-one billion, one hundred fifteen million, twenty thousand, fifty-four".