21154535604677 has 2 divisors, whose sum is σ = 21154535604678. Its totient is φ = 21154535604676.

The previous prime is 21154535604613. The next prime is 21154535604689. The reversal of 21154535604677 is 77640653545112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17948999863876 + 3205535740801 = 4236626^2 + 1790401^2 .

It is a cyclic number.

It is not a de Polignac number, because 21154535604677 - 2⁶ = 21154535604613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21154535664677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10577267802338 + 10577267802339.

It is an arithmetic number, because the mean of its divisors is an integer number (10577267802339).

Almost surely, 2^{21154535604677} is an apocalyptic number.

It is an amenable number.

21154535604677 is a deficient number, since it is larger than the sum of its proper divisors (1).

21154535604677 is an equidigital number, since it uses as much as digits as its factorization.

21154535604677 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21168000, while the sum is 56.

The spelling of 21154535604677 in words is "twenty-one trillion, one hundred fifty-four billion, five hundred thirty-five million, six hundred four thousand, six hundred seventy-seven".