21137020993 has 8 divisors (see below), whose sum is σ = 23088407616. Its totient is φ = 19190607600.

The previous prime is 21137020981. The next prime is 21137021021. The reversal of 21137020993 is 39902073112.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21137020993 - 2⁹ = 21137020481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21137020943) 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, 1234413 + ... + 1251418.

It is an arithmetic number, because the mean of its divisors is an integer number (2886050952).

Almost surely, 2^21137020993 is an apocalyptic number.

It is an amenable number.

21137020993 is a deficient number, since it is larger than the sum of its proper divisors (1951386623).

21137020993 is a wasteful number, since it uses less digits than its factorization.

21137020993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2486615.

The product of its (nonzero) digits is 20412, while the sum is 37.

The spelling of 21137020993 in words is "twenty-one billion, one hundred thirty-seven million, twenty thousand, nine hundred ninety-three".