1320764257 has 4 divisors (see below), whose sum is σ = 1321947796. Its totient is φ = 1319580720.

The previous prime is 1320764251. The next prime is 1320764261. The reversal of 1320764257 is 7524670231.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7524670231 = 13 ⋅578820787.

It can be written as a sum of positive squares in 2 ways, for example, as 733380561 + 587383696 = 27081^2 + 24236^2 .

It is a cyclic number.

It is not a de Polignac number, because 1320764257 - 2⁷ = 1320764129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1320764251) 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, 590094 + ... + 592327.

It is an arithmetic number, because the mean of its divisors is an integer number (330486949).

Almost surely, 2^1320764257 is an apocalyptic number.

It is an amenable number.

1320764257 is a deficient number, since it is larger than the sum of its proper divisors (1183539).

1320764257 is a wasteful number, since it uses less digits than its factorization.

1320764257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1183538.

The product of its (nonzero) digits is 70560, while the sum is 37.

The square root of 1320764257 is about 36342.3204680163. The cubic root of 1320764257 is about 1097.1729768031.

The spelling of 1320764257 in words is "one billion, three hundred twenty million, seven hundred sixty-four thousand, two hundred fifty-seven".