21507536443363 has 4 divisors (see below), whose sum is σ = 22201327941568. Its totient is φ = 20813744945160.

The previous prime is 21507536443241. The next prime is 21507536443397. The reversal of 21507536443363 is 36334463570512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21507536443363 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21507536443363.

It is not an unprimeable number, because it can be changed into a prime (21507546443363) 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, 346895749056 + ... + 346895749117.

It is an arithmetic number, because the mean of its divisors is an integer number (5550331985392).

Almost surely, 2^{21507536443363} is an apocalyptic number.

21507536443363 is a deficient number, since it is larger than the sum of its proper divisors (693791498205).

21507536443363 is an equidigital number, since it uses as much as digits as its factorization.

21507536443363 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 693791498204.

The product of its (nonzero) digits is 16329600, while the sum is 52.

The spelling of 21507536443363 in words is "twenty-one trillion, five hundred seven billion, five hundred thirty-six million, four hundred forty-three thousand, three hundred sixty-three".