21612640773571 has 2 divisors, whose sum is σ = 21612640773572. Its totient is φ = 21612640773570.

The previous prime is 21612640773533. The next prime is 21612640773583. The reversal of 21612640773571 is 17537704621612.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21612640773571 - 2⁷ = 21612640773443 is a prime.

It is not a weakly prime, because it can be changed into another prime (21612640773271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10806320386785 + 10806320386786.

It is an arithmetic number, because the mean of its divisors is an integer number (10806320386786).

Almost surely, 2^{21612640773571} is an apocalyptic number.

21612640773571 is a deficient number, since it is larger than the sum of its proper divisors (1).

21612640773571 is an equidigital number, since it uses as much as digits as its factorization.

21612640773571 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2963520, while the sum is 52.

The spelling of 21612640773571 in words is "twenty-one trillion, six hundred twelve billion, six hundred forty million, seven hundred seventy-three thousand, five hundred seventy-one".