1225517257 has 4 divisors (see below), whose sum is σ = 1278800640. Its totient is φ = 1172233876.

The previous prime is 1225517231. The next prime is 1225517287. The reversal of 1225517257 is 7527155221.

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 a cyclic number.

It is not a de Polignac number, because 1225517257 - 2⁷ = 1225517129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1225517207) 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, 26641657 + ... + 26641702.

It is an arithmetic number, because the mean of its divisors is an integer number (319700160).

Almost surely, 2^1225517257 is an apocalyptic number.

It is an amenable number.

1225517257 is a deficient number, since it is larger than the sum of its proper divisors (53283383).

1225517257 is an equidigital number, since it uses as much as digits as its factorization.

1225517257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53283382.

The product of its digits is 49000, while the sum is 37.

The square root of 1225517257 is about 35007.3886058358. The cubic root of 1225517257 is about 1070.1380603292.

The spelling of 1225517257 in words is "one billion, two hundred twenty-five million, five hundred seventeen thousand, two hundred fifty-seven".