642254711557 has 2 divisors, whose sum is σ = 642254711558. Its totient is φ = 642254711556.

The previous prime is 642254711513. The next prime is 642254711587. The reversal of 642254711557 is 755117452246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 404026768161 + 238227943396 = 635631^2 + 488086^2 .

It is a cyclic number.

It is not a de Polignac number, because 642254711557 - 2⁷ = 642254711429 is a prime.

It is a super-2 number, since 2×642254711557² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 642254711557.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642254711587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321127355778 + 321127355779.

It is an arithmetic number, because the mean of its divisors is an integer number (321127355779).

Almost surely, 2^642254711557 is an apocalyptic number.

It is an amenable number.

642254711557 is a deficient number, since it is larger than the sum of its proper divisors (1).

642254711557 is an equidigital number, since it uses as much as digits as its factorization.

642254711557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2352000, while the sum is 49.

The spelling of 642254711557 in words is "six hundred forty-two billion, two hundred fifty-four million, seven hundred eleven thousand, five hundred fifty-seven".