1225681257 has 4 divisors (see below), whose sum is σ = 1634241680. Its totient is φ = 817120836.

The previous prime is 1225681253. The next prime is 1225681291. The reversal of 1225681257 is 7521865221.

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 1225681257 - 2² = 1225681253 is a prime.

It is a super-2 number, since 2×1225681257² = 3004589087522200098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1225681253) 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, 204280207 + ... + 204280212.

It is an arithmetic number, because the mean of its divisors is an integer number (408560420).

Almost surely, 2^1225681257 is an apocalyptic number.

It is an amenable number.

1225681257 is a deficient number, since it is larger than the sum of its proper divisors (408560423).

1225681257 is an equidigital number, since it uses as much as digits as its factorization.

1225681257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408560422.

The product of its digits is 67200, while the sum is 39.

The square root of 1225681257 is about 35009.7308901397. The cubic root of 1225681257 is about 1070.1857938645.

The spelling of 1225681257 in words is "one billion, two hundred twenty-five million, six hundred eighty-one thousand, two hundred fifty-seven".