21660354110623 has 2 divisors, whose sum is σ = 21660354110624. Its totient is φ = 21660354110622.

The previous prime is 21660354110567. The next prime is 21660354110669. The reversal of 21660354110623 is 32601145306612.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21660354110623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21660354111623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10830177055311 + 10830177055312.

It is an arithmetic number, because the mean of its divisors is an integer number (10830177055312).

Almost surely, 2^{21660354110623} is an apocalyptic number.

21660354110623 is a deficient number, since it is larger than the sum of its proper divisors (1).

21660354110623 is an equidigital number, since it uses as much as digits as its factorization.

21660354110623 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 155520, while the sum is 40.

The spelling of 21660354110623 in words is "twenty-one trillion, six hundred sixty billion, three hundred fifty-four million, one hundred ten thousand, six hundred twenty-three".