21515636054 has 12 divisors (see below), whose sum is σ = 35474127612. Its totient is φ = 9779834460.

The previous prime is 21515635997. The next prime is 21515636059. The reversal of 21515636054 is 45063651512.

It is a junction number, because it is equal to n+sod(n) for n = 21515635999 and 21515636017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21515636059) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 44453552 + ... + 44454035.

It is an arithmetic number, because the mean of its divisors is an integer number (2956177301).

Almost surely, 2^21515636054 is an apocalyptic number.

21515636054 is a deficient number, since it is larger than the sum of its proper divisors (13958491558).

21515636054 is a wasteful number, since it uses less digits than its factorization.

21515636054 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88907611 (or 88907600 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 38.

The spelling of 21515636054 in words is "twenty-one billion, five hundred fifteen million, six hundred thirty-six thousand, fifty-four".