257645403405 has 96 divisors (see below), whose sum is σ = 510519076704. Its totient is φ = 119077060608.

The previous prime is 257645403383. The next prime is 257645403409. The reversal of 257645403405 is 504304546752.

257645403405 is a `hidden beast` number, since 2 + 5 + 7 + 64 + 540 + 3 + 40 + 5 = 666.

It can be written as a sum of positive squares in 16 ways, for example, as 89566722729 + 168078680676 = 299277^2 + 409974^2 .

It is not a de Polignac number, because 257645403405 - 2¹⁸ = 257645141261 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257645403409) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3915537 + ... + 3980793.

It is an arithmetic number, because the mean of its divisors is an integer number (5317907049).

Almost surely, 2^257645403405 is an apocalyptic number.

It is an amenable number.

257645403405 is a deficient number, since it is larger than the sum of its proper divisors (252873673299).

257645403405 is a wasteful number, since it uses less digits than its factorization.

257645403405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65695 (or 65692 counting only the distinct ones).

The product of its (nonzero) digits is 2016000, while the sum is 45.

The spelling of 257645403405 in words is "two hundred fifty-seven billion, six hundred forty-five million, four hundred three thousand, four hundred five".