21537713453 has 4 divisors (see below), whose sum is σ = 21538241760. Its totient is φ = 21537185148.

The previous prime is 21537713411. The next prime is 21537713479. The reversal of 21537713453 is 35431773512.

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 not a de Polignac number, because 21537713453 - 2¹⁰ = 21537712429 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21537713453.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21537713753) 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, 197375 + ... + 286412.

It is an arithmetic number, because the mean of its divisors is an integer number (5384560440).

Almost surely, 2^21537713453 is an apocalyptic number.

It is an amenable number.

21537713453 is a deficient number, since it is larger than the sum of its proper divisors (528307).

21537713453 is an equidigital number, since it uses as much as digits as its factorization.

21537713453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528306.

The product of its digits is 264600, while the sum is 41.

The spelling of 21537713453 in words is "twenty-one billion, five hundred thirty-seven million, seven hundred thirteen thousand, four hundred fifty-three".