21013644837 has 8 divisors (see below), whose sum is σ = 28035108736. Its totient is φ = 14000638752.

The previous prime is 21013644829. The next prime is 21013644851. The reversal of 21013644837 is 73844631012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21013644837 - 2³ = 21013644829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21013644795 and 21013644804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21013644887) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2108653 + ... + 2118594.

It is an arithmetic number, because the mean of its divisors is an integer number (3504388592).

Almost surely, 2^21013644837 is an apocalyptic number.

It is an amenable number.

21013644837 is a deficient number, since it is larger than the sum of its proper divisors (7021463899).

21013644837 is a wasteful number, since it uses less digits than its factorization.

21013644837 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4228907.

The product of its (nonzero) digits is 96768, while the sum is 39.

The spelling of 21013644837 in words is "twenty-one billion, thirteen million, six hundred forty-four thousand, eight hundred thirty-seven".