1331215257 has 8 divisors (see below), whose sum is σ = 1808443584. Its totient is φ = 870731888.

The previous prime is 1331215241. The next prime is 1331215271. The reversal of 1331215257 is 7525121331.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1331215257 - 2⁴ = 1331215241 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1331285257) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4186053 + ... + 4186370.

It is an arithmetic number, because the mean of its divisors is an integer number (226055448).

Almost surely, 2^1331215257 is an apocalyptic number.

It is an amenable number.

1331215257 is a deficient number, since it is larger than the sum of its proper divisors (477228327).

1331215257 is an equidigital number, since it uses as much as digits as its factorization.

1331215257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8372479.

The product of its digits is 6300, while the sum is 30.

The square root of 1331215257 is about 36485.8226849827. The cubic root of 1331215257 is about 1100.0592962526.

Adding to 1331215257 its reverse (7525121331), we get a palindrome (8856336588).

The spelling of 1331215257 in words is "one billion, three hundred thirty-one million, two hundred fifteen thousand, two hundred fifty-seven".