21602421640801 has 6 divisors (see below), whose sum is σ = 22947901189670. Its totient is φ = 20331690955776.

The previous prime is 21602421640781. The next prime is 21602421640831. The reversal of 21602421640801 is 10804612420612.

It can be written as a sum of positive squares in 3 ways, for example, as 10352595827025 + 11249825813776 = 3217545^2 + 3354076^2 .

It is not a de Polignac number, because 21602421640801 - 2²⁵ = 21602388086369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21602421640831) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37374431616 + ... + 37374432193.

Almost surely, 2^{21602421640801} is an apocalyptic number.

It is an amenable number.

21602421640801 is a deficient number, since it is larger than the sum of its proper divisors (1345479548869).

21602421640801 is an equidigital number, since it uses as much as digits as its factorization.

21602421640801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74748863843 (or 74748863826 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 37.

The spelling of 21602421640801 in words is "twenty-one trillion, six hundred two billion, four hundred twenty-one million, six hundred forty thousand, eight hundred one".