1216744257 has 4 divisors (see below), whose sum is σ = 1622325680. Its totient is φ = 811162836.

The previous prime is 1216744237. The next prime is 1216744261. The reversal of 1216744257 is 7524476121.

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.

It is not a de Polignac number, because 1216744257 - 2⁷ = 1216744129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216744237) 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, 202790707 + ... + 202790712.

It is an arithmetic number, because the mean of its divisors is an integer number (405581420).

Almost surely, 2^1216744257 is an apocalyptic number.

It is an amenable number.

1216744257 is a deficient number, since it is larger than the sum of its proper divisors (405581423).

1216744257 is an equidigital number, since it uses as much as digits as its factorization.

1216744257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405581422.

The product of its digits is 94080, while the sum is 39.

The square root of 1216744257 is about 34881.8614325555. The cubic root of 1216744257 is about 1067.5783756696.

The spelling of 1216744257 in words is "one billion, two hundred sixteen million, seven hundred forty-four thousand, two hundred fifty-seven".