21031497505 has 8 divisors (see below), whose sum is σ = 26335092672. Its totient is φ = 16093667568.

The previous prime is 21031497497. The next prime is 21031497523. The reversal of 21031497505 is 50579413012.

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 21031497505 - 2³ = 21031497497 is a prime.

It is a Duffinian 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, 91441179 + ... + 91441408.

It is an arithmetic number, because the mean of its divisors is an integer number (3291886584).

Almost surely, 2^21031497505 is an apocalyptic number.

It is an amenable number.

21031497505 is a deficient number, since it is larger than the sum of its proper divisors (5303595167).

21031497505 is a wasteful number, since it uses less digits than its factorization.

21031497505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182882615.

The product of its (nonzero) digits is 37800, while the sum is 37.

The spelling of 21031497505 in words is "twenty-one billion, thirty-one million, four hundred ninety-seven thousand, five hundred five".