1280373257 has 4 divisors (see below), whose sum is σ = 1280449296. Its totient is φ = 1280297220.

The previous prime is 1280373251. The next prime is 1280373277. The reversal of 1280373257 is 7523730821.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1280373257 - 2¹⁸ = 1280111113 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1280373257.

It is not an unprimeable number, because it can be changed into a prime (1280373251) 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, 263 + ... + 50604.

It is an arithmetic number, because the mean of its divisors is an integer number (320112324).

Almost surely, 2^1280373257 is an apocalyptic number.

It is an amenable number.

1280373257 is a deficient number, since it is larger than the sum of its proper divisors (76039).

1280373257 is an equidigital number, since it uses as much as digits as its factorization.

1280373257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76038.

The product of its (nonzero) digits is 70560, while the sum is 38.

The square root of 1280373257 is about 35782.3036849222. The cubic root of 1280373257 is about 1085.8725754827.

The spelling of 1280373257 in words is "one billion, two hundred eighty million, three hundred seventy-three thousand, two hundred fifty-seven".