21515013334 has 16 divisors (see below), whose sum is σ = 33078519216. Its totient is φ = 10492020000.

The previous prime is 21515013301. The next prime is 21515013353. The reversal of 21515013334 is 43331051512.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 781317 + ... + 808384.

It is an arithmetic number, because the mean of its divisors is an integer number (2067407451).

Almost surely, 2^21515013334 is an apocalyptic number.

21515013334 is a deficient number, since it is larger than the sum of its proper divisors (11563505882).

21515013334 is a wasteful number, since it uses less digits than its factorization.

21515013334 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1589871.

The product of its (nonzero) digits is 5400, while the sum is 28.

Adding to 21515013334 its reverse (43331051512), we get a palindrome (64846064846).

It can be divided in two parts, 215150 and 13334, that added together give a square (228484 = 478²).

The spelling of 21515013334 in words is "twenty-one billion, five hundred fifteen million, thirteen thousand, three hundred thirty-four".