21507464254213 has 4 divisors (see below), whose sum is σ = 24579959147680. Its totient is φ = 18434969360748.

The previous prime is 21507464254147. The next prime is 21507464254231. The reversal of 21507464254213 is 31245246470512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21507464254213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21507464254513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1536247446723 + ... + 1536247446736.

It is an arithmetic number, because the mean of its divisors is an integer number (6144989786920).

Almost surely, 2^{21507464254213} is an apocalyptic number.

It is an amenable number.

21507464254213 is a deficient number, since it is larger than the sum of its proper divisors (3072494893467).

21507464254213 is an equidigital number, since it uses as much as digits as its factorization.

21507464254213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3072494893466.

The product of its (nonzero) digits is 1612800, while the sum is 46.

The spelling of 21507464254213 in words is "twenty-one trillion, five hundred seven billion, four hundred sixty-four million, two hundred fifty-four thousand, two hundred thirteen".