1225256618 has 4 divisors (see below), whose sum is σ = 1837884930. Its totient is φ = 612628308.

The previous prime is 1225256609. The next prime is 1225256639. The reversal of 1225256618 is 8166525221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8166525221 = 211 ⋅38703911.

It can be written as a sum of positive squares in only one way, i.e., 993699529 + 231557089 = 31523^2 + 15217^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 306314153 + ... + 306314156.

Almost surely, 2^1225256618 is an apocalyptic number.

1225256618 is a deficient number, since it is larger than the sum of its proper divisors (612628312).

1225256618 is an equidigital number, since it uses as much as digits as its factorization.

1225256618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 612628311.

The product of its digits is 57600, while the sum is 38.

The square root of 1225256618 is about 35003.6657794580. The cubic root of 1225256618 is about 1070.0621904634.

The spelling of 1225256618 in words is "one billion, two hundred twenty-five million, two hundred fifty-six thousand, six hundred eighteen".