3947426557 has 2 divisors, whose sum is σ = 3947426558. Its totient is φ = 3947426556.

The previous prime is 3947426533. The next prime is 3947426579. The reversal of 3947426557 is 7556247493.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3932418681 + 15007876 = 62709^2 + 3874^2 .

It is a cyclic number.

It is not a de Polignac number, because 3947426557 - 2¹⁵ = 3947393789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3947426057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1973713278 + 1973713279.

It is an arithmetic number, because the mean of its divisors is an integer number (1973713279).

Almost surely, 2^3947426557 is an apocalyptic number.

It is an amenable number.

3947426557 is a deficient number, since it is larger than the sum of its proper divisors (1).

3947426557 is an equidigital number, since it uses as much as digits as its factorization.

3947426557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6350400, while the sum is 52.

The square root of 3947426557 is about 62828.5489009574. The cubic root of 3947426557 is about 1580.4157637096.

The spelling of 3947426557 in words is "three billion, nine hundred forty-seven million, four hundred twenty-six thousand, five hundred fifty-seven".