21620536176697 has 2 divisors, whose sum is σ = 21620536176698. Its totient is φ = 21620536176696.

The previous prime is 21620536176689. The next prime is 21620536176739. The reversal of 21620536176697 is 79667163502612.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18747202678416 + 2873333498281 = 4329804^2 + 1695091^2 .

It is a cyclic number.

It is not a de Polignac number, because 21620536176697 - 2³ = 21620536176689 is a prime.

It is not a weakly prime, because it can be changed into another prime (21620536176637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10810268088348 + 10810268088349.

It is an arithmetic number, because the mean of its divisors is an integer number (10810268088349).

Almost surely, 2^{21620536176697} is an apocalyptic number.

It is an amenable number.

21620536176697 is a deficient number, since it is larger than the sum of its proper divisors (1).

21620536176697 is an equidigital number, since it uses as much as digits as its factorization.

21620536176697 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34292160, while the sum is 61.

The spelling of 21620536176697 in words is "twenty-one trillion, six hundred twenty billion, five hundred thirty-six million, one hundred seventy-six thousand, six hundred ninety-seven".