257661623 has 2 divisors, whose sum is σ = 257661624. Its totient is φ = 257661622.

The previous prime is 257661601. The next prime is 257661629. The reversal of 257661623 is 326166752.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 257661623 - 2¹² = 257657527 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257661629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128830811 + 128830812.

It is an arithmetic number, because the mean of its divisors is an integer number (128830812).

Almost surely, 2^257661623 is an apocalyptic number.

257661623 is a deficient number, since it is larger than the sum of its proper divisors (1).

257661623 is an equidigital number, since it uses as much as digits as its factorization.

257661623 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 38.

The square root of 257661623 is about 16051.8417323371. The cubic root of 257661623 is about 636.3312415253.

The spelling of 257661623 in words is "two hundred fifty-seven million, six hundred sixty-one thousand, six hundred twenty-three".