21021631668683 has 2 divisors, whose sum is σ = 21021631668684. Its totient is φ = 21021631668682.

The previous prime is 21021631668671. The next prime is 21021631668689. The reversal of 21021631668683 is 38686613612012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21021631668683 - 2¹⁴ = 21021631652299 is a prime.

It is a super-2 number, since 2×21021631668683² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21021631668689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510815834341 + 10510815834342.

It is an arithmetic number, because the mean of its divisors is an integer number (10510815834342).

Almost surely, 2^{21021631668683} is an apocalyptic number.

21021631668683 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021631668683 is an equidigital number, since it uses as much as digits as its factorization.

21021631668683 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2985984, while the sum is 53.

The spelling of 21021631668683 in words is "twenty-one trillion, twenty-one billion, six hundred thirty-one million, six hundred sixty-eight thousand, six hundred eighty-three".