21357720765467 has 2 divisors, whose sum is σ = 21357720765468. Its totient is φ = 21357720765466.

The previous prime is 21357720765361. The next prime is 21357720765487. The reversal of 21357720765467 is 76456702775312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21357720765467 - 2⁸ = 21357720765211 is a prime.

It is not a weakly prime, because it can be changed into another prime (21357720765487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10678860382733 + 10678860382734.

It is an arithmetic number, because the mean of its divisors is an integer number (10678860382734).

Almost surely, 2^{21357720765467} is an apocalyptic number.

21357720765467 is a deficient number, since it is larger than the sum of its proper divisors (1).

21357720765467 is an equidigital number, since it uses as much as digits as its factorization.

21357720765467 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103723200, while the sum is 62.

The spelling of 21357720765467 in words is "twenty-one trillion, three hundred fifty-seven billion, seven hundred twenty million, seven hundred sixty-five thousand, four hundred sixty-seven".