15521534420 has 48 divisors (see below), whose sum is σ = 37954562688. Its totient is φ = 5221257600.

The previous prime is 15521534389. The next prime is 15521534423. The reversal of 15521534420 is 2443512551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15521534423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1038506 + ... + 1053345.

It is an arithmetic number, because the mean of its divisors is an integer number (790720056).

Almost surely, 2^15521534420 is an apocalyptic number.

15521534420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15521534420 is an abundant number, since it is smaller than the sum of its proper divisors (22433028268).

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

15521534420 is a wasteful number, since it uses less digits than its factorization.

15521534420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2091920 (or 2091918 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 32.

The spelling of 15521534420 in words is "fifteen billion, five hundred twenty-one million, five hundred thirty-four thousand, four hundred twenty".