21001513524 has 24 divisors (see below), whose sum is σ = 49453108320. Its totient is φ = 6936279264.

The previous prime is 21001513471. The next prime is 21001513541. The reversal of 21001513524 is 42531510012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21001513494 and 21001513503.

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, 8026794 + ... + 8029409.

It is an arithmetic number, because the mean of its divisors is an integer number (2060546180).

Almost surely, 2^21001513524 is an apocalyptic number.

It is an amenable number.

21001513524 is an abundant number, since it is smaller than the sum of its proper divisors (28451594796).

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

21001513524 is a wasteful number, since it uses less digits than its factorization.

21001513524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16056319 (or 16056317 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

The spelling of 21001513524 in words is "twenty-one billion, one million, five hundred thirteen thousand, five hundred twenty-four".