1225518857 has 4 divisors (see below), whose sum is σ = 1226260116. Its totient is φ = 1224777600.

The previous prime is 1225518851. The next prime is 1225518871. The reversal of 1225518857 is 7588155221.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7588155221 = 229 ⋅33136049.

It can be written as a sum of positive squares in 2 ways, for example, as 957345481 + 268173376 = 30941^2 + 16376^2 .

It is a cyclic number.

It is not a de Polignac number, because 1225518857 - 2⁶ = 1225518793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1225518851) 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, 368144 + ... + 371457.

It is an arithmetic number, because the mean of its divisors is an integer number (306565029).

Almost surely, 2^1225518857 is an apocalyptic number.

It is an amenable number.

1225518857 is a deficient number, since it is larger than the sum of its proper divisors (741259).

1225518857 is an equidigital number, since it uses as much as digits as its factorization.

1225518857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 741258.

The product of its digits is 224000, while the sum is 44.

The square root of 1225518857 is about 35007.4114581470. The cubic root of 1225518857 is about 1070.1385260428.

The spelling of 1225518857 in words is "one billion, two hundred twenty-five million, five hundred eighteen thousand, eight hundred fifty-seven".