1253556666 has 24 divisors (see below), whose sum is σ = 2717182260. Its totient is φ = 417676416.

The previous prime is 1253556631. The next prime is 1253556701. The reversal of 1253556666 is 6666553521.

It is an interprime number because it is at equal distance from previous prime (1253556631) and next prime (1253556701).

It can be written as a sum of positive squares in 2 ways, for example, as 1080502641 + 173054025 = 32871^2 + 13155^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 33616 + ... + 60308.

Almost surely, 2^1253556666 is an apocalyptic number.

1253556666 is an abundant number, since it is smaller than the sum of its proper divisors (1463625594).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1253556666 is a wasteful number, since it uses less digits than its factorization.

1253556666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29310 (or 29307 counting only the distinct ones).

The product of its digits is 972000, while the sum is 45.

The square root of 1253556666 is about 35405.6021838353. The cubic root of 1253556666 is about 1078.2380581525.

The spelling of 1253556666 in words is "one billion, two hundred fifty-three million, five hundred fifty-six thousand, six hundred sixty-six".