1290947257 has 4 divisors (see below), whose sum is σ = 1308631540. Its totient is φ = 1273262976.

The previous prime is 1290947239. The next prime is 1290947263. The reversal of 1290947257 is 7527490921.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 400760361 + 890186896 = 20019^2 + 29836^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1290947257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1290948257) 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, 8842032 + ... + 8842177.

It is an arithmetic number, because the mean of its divisors is an integer number (327157885).

Almost surely, 2^1290947257 is an apocalyptic number.

It is an amenable number.

1290947257 is a deficient number, since it is larger than the sum of its proper divisors (17684283).

1290947257 is an equidigital number, since it uses as much as digits as its factorization.

1290947257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17684282.

The product of its (nonzero) digits is 317520, while the sum is 46.

The square root of 1290947257 is about 35929.7544800963. The cubic root of 1290947257 is about 1088.8536209415.

The spelling of 1290947257 in words is "one billion, two hundred ninety million, nine hundred forty-seven thousand, two hundred fifty-seven".