1331490257 has 4 divisors (see below), whose sum is σ = 1332205296. Its totient is φ = 1330775220.

The previous prime is 1331490241. The next prime is 1331490283. The reversal of 1331490257 is 7520941331.

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 an emirpimes, since its reverse is a distinct semiprime: 7520941331 = 79 ⋅95201789.

It is a cyclic number.

It is not a de Polignac number, because 1331490257 - 2⁴ = 1331490241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1331490287) 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 in 3 ways as a sum of consecutive naturals, for example, 354719 + ... + 358452.

It is an arithmetic number, because the mean of its divisors is an integer number (333051324).

Almost surely, 2^1331490257 is an apocalyptic number.

It is an amenable number.

1331490257 is a deficient number, since it is larger than the sum of its proper divisors (715039).

1331490257 is an equidigital number, since it uses as much as digits as its factorization.

1331490257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 715038.

The product of its (nonzero) digits is 22680, while the sum is 35.

The square root of 1331490257 is about 36489.5910774566. The cubic root of 1331490257 is about 1100.1350404460.

The spelling of 1331490257 in words is "one billion, three hundred thirty-one million, four hundred ninety thousand, two hundred fifty-seven".