21552201761 has 2 divisors, whose sum is σ = 21552201762. Its totient is φ = 21552201760.

The previous prime is 21552201719. The next prime is 21552201767. The reversal of 21552201761 is 16710225512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14742816400 + 6809385361 = 121420^2 + 82519^2 .

It is a cyclic number.

It is not a de Polignac number, because 21552201761 - 2¹⁰ = 21552200737 is a prime.

It is a super-2 number, since 2×21552201761² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21552201767) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10776100880 + 10776100881.

It is an arithmetic number, because the mean of its divisors is an integer number (10776100881).

Almost surely, 2^21552201761 is an apocalyptic number.

It is an amenable number.

21552201761 is a deficient number, since it is larger than the sum of its proper divisors (1).

21552201761 is an equidigital number, since it uses as much as digits as its factorization.

21552201761 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8400, while the sum is 32.

The spelling of 21552201761 in words is "twenty-one billion, five hundred fifty-two million, two hundred one thousand, seven hundred sixty-one".