21602421640831 has 2 divisors, whose sum is σ = 21602421640832. Its totient is φ = 21602421640830.

The previous prime is 21602421640781. The next prime is 21602421640841. The reversal of 21602421640831 is 13804612420612.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21602421640831 - 2¹³ = 21602421632639 is a prime.

It is a super-2 number, since 2×21602421640831² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21602421640841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10801210820415 + 10801210820416.

It is an arithmetic number, because the mean of its divisors is an integer number (10801210820416).

Almost surely, 2^{21602421640831} is an apocalyptic number.

21602421640831 is a deficient number, since it is larger than the sum of its proper divisors (1).

21602421640831 is an equidigital number, since it uses as much as digits as its factorization.

21602421640831 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 110592, while the sum is 40.

The spelling of 21602421640831 in words is "twenty-one trillion, six hundred two billion, four hundred twenty-one million, six hundred forty thousand, eight hundred thirty-one".