21066562331 has 2 divisors, whose sum is σ = 21066562332. Its totient is φ = 21066562330.

The previous prime is 21066562327. The next prime is 21066562351. The reversal of 21066562331 is 13326566012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21066562331 - 2² = 21066562327 is a prime.

It is a super-2 number, since 2×21066562331² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21066562291 and 21066562300.

It is not a weakly prime, because it can be changed into another prime (21066562351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10533281165 + 10533281166.

It is an arithmetic number, because the mean of its divisors is an integer number (10533281166).

Almost surely, 2^21066562331 is an apocalyptic number.

21066562331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21066562331 is an equidigital number, since it uses as much as digits as its factorization.

21066562331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38880, while the sum is 35.

The spelling of 21066562331 in words is "twenty-one billion, sixty-six million, five hundred sixty-two thousand, three hundred thirty-one".