21566380032001 has 4 divisors (see below), whose sum is σ = 24647291465152. Its totient is φ = 18485468598852.

The previous prime is 21566380031957. The next prime is 21566380032007. The reversal of 21566380032001 is 10023008366512.

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 21566380032001 - 2⁹ = 21566380031489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21566380032007) 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, 1540455716565 + ... + 1540455716578.

It is an arithmetic number, because the mean of its divisors is an integer number (6161822866288).

Almost surely, 2^{21566380032001} is an apocalyptic number.

It is an amenable number.

21566380032001 is a deficient number, since it is larger than the sum of its proper divisors (3080911433151).

21566380032001 is an equidigital number, since it uses as much as digits as its factorization.

21566380032001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3080911433150.

The product of its (nonzero) digits is 51840, while the sum is 37.

Adding to 21566380032001 its reverse (10023008366512), we get a palindrome (31589388398513).

The spelling of 21566380032001 in words is "twenty-one trillion, five hundred sixty-six billion, three hundred eighty million, thirty-two thousand, one".