21515442130 has 64 divisors (see below), whose sum is σ = 47687447808. Its totient is φ = 6806073600.

The previous prime is 21515442073. The next prime is 21515442211. The reversal of 21515442130 is 3124451512.

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 31 ways as a sum of consecutive naturals, for example, 2590264 + ... + 2598556.

It is an arithmetic number, because the mean of its divisors is an integer number (745116372).

Almost surely, 2^21515442130 is an apocalyptic number.

21515442130 is an abundant number, since it is smaller than the sum of its proper divisors (26172005678).

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

21515442130 is a wasteful number, since it uses less digits than its factorization.

21515442130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11171.

The product of its (nonzero) digits is 4800, while the sum is 28.

Adding to 21515442130 its reverse (3124451512), we get a palindrome (24639893642).

The spelling of 21515442130 in words is "twenty-one billion, five hundred fifteen million, four hundred forty-two thousand, one hundred thirty".