1557638263 has 2 divisors, whose sum is σ = 1557638264. Its totient is φ = 1557638262.

The previous prime is 1557638239. The next prime is 1557638267. The reversal of 1557638263 is 3628367551.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1557638263 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1557638267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 778819131 + 778819132.

It is an arithmetic number, because the mean of its divisors is an integer number (778819132).

Almost surely, 2^1557638263 is an apocalyptic number.

1557638263 is a deficient number, since it is larger than the sum of its proper divisors (1).

1557638263 is an equidigital number, since it uses as much as digits as its factorization.

1557638263 is an evil number, because the sum of its binary digits is even.

The product of its digits is 907200, while the sum is 46.

The square root of 1557638263 is about 39466.9261914327. The cubic root of 1557638263 is about 1159.1924281528.

The spelling of 1557638263 in words is "one billion, five hundred fifty-seven million, six hundred thirty-eight thousand, two hundred sixty-three".