21507372240405 has 8 divisors (see below), whose sum is σ = 34411795584672. Its totient is φ = 11470598528208.

The previous prime is 21507372240371. The next prime is 21507372240433. The reversal of 21507372240405 is 50404227370512.

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

It is a de Polignac number, because none of the positive numbers 2^k-21507372240405 is a prime.

It is a super-2 number, since 2×21507372240405² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 716912407999 + ... + 716912408028.

It is an arithmetic number, because the mean of its divisors is an integer number (4301474448084).

Almost surely, 2^{21507372240405} is an apocalyptic number.

It is an amenable number.

21507372240405 is a deficient number, since it is larger than the sum of its proper divisors (12904423344267).

21507372240405 is a wasteful number, since it uses less digits than its factorization.

21507372240405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1433824816035.

The product of its (nonzero) digits is 470400, while the sum is 42.

The spelling of 21507372240405 in words is "twenty-one trillion, five hundred seven billion, three hundred seventy-two million, two hundred forty thousand, four hundred five".