21651767411753 has 2 divisors, whose sum is σ = 21651767411754. Its totient is φ = 21651767411752.

The previous prime is 21651767411749. The next prime is 21651767411779. The reversal of 21651767411753 is 35711476715612.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15508765505689 + 6143001906064 = 3938117^2 + 2478508^2 .

It is a cyclic number.

It is not a de Polignac number, because 21651767411753 - 2² = 21651767411749 is a prime.

It is not a weakly prime, because it can be changed into another prime (21651767441753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10825883705876 + 10825883705877.

It is an arithmetic number, because the mean of its divisors is an integer number (10825883705877).

Almost surely, 2^{21651767411753} is an apocalyptic number.

It is an amenable number.

21651767411753 is a deficient number, since it is larger than the sum of its proper divisors (1).

21651767411753 is an equidigital number, since it uses as much as digits as its factorization.

21651767411753 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7408800, while the sum is 56.

The spelling of 21651767411753 in words is "twenty-one trillion, six hundred fifty-one billion, seven hundred sixty-seven million, four hundred eleven thousand, seven hundred fifty-three".