257208746276021 has 4 divisors (see below), whose sum is σ = 257348003855712. Its totient is φ = 257069488696332.

The previous prime is 257208746275979. The next prime is 257208746276071. The reversal of 257208746276021 is 120672647802752.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 257208746276021 - 2³⁸ = 256933868369077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257208746276071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69628787075 + ... + 69628790768.

It is an arithmetic number, because the mean of its divisors is an integer number (64337000963928).

Almost surely, 2^{257208746276021} is an apocalyptic number.

It is an amenable number.

257208746276021 is a deficient number, since it is larger than the sum of its proper divisors (139257579691).

257208746276021 is a wasteful number, since it uses less digits than its factorization.

257208746276021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139257579690.

The product of its (nonzero) digits is 31610880, while the sum is 59.

The spelling of 257208746276021 in words is "two hundred fifty-seven trillion, two hundred eight billion, seven hundred forty-six million, two hundred seventy-six thousand, twenty-one".