21002537424 has 40 divisors (see below), whose sum is σ = 59188970592. Its totient is φ = 6364405120.

The previous prime is 21002537329. The next prime is 21002537431. The reversal of 21002537424 is 42473520012.

It is a super-2 number, since 2×21002537424² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21002537391 and 21002537400.

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, 19888239 + ... + 19889294.

Almost surely, 2^21002537424 is an apocalyptic number.

21002537424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21002537424 is an abundant number, since it is smaller than the sum of its proper divisors (38186433168).

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

21002537424 is a wasteful number, since it uses less digits than its factorization.

21002537424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39777555 (or 39777549 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 30.

The spelling of 21002537424 in words is "twenty-one billion, two million, five hundred thirty-seven thousand, four hundred twenty-four".