1251236778 has 32 divisors (see below), whose sum is σ = 2743718400. Its totient is φ = 377253360.

The previous prime is 1251236761. The next prime is 1251236803. The reversal of 1251236778 is 8776321521.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34500 + ... + 60767.

It is an arithmetic number, because the mean of its divisors is an integer number (85741200).

Almost surely, 2^1251236778 is an apocalyptic number.

1251236778 is an abundant number, since it is smaller than the sum of its proper divisors (1492481622).

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

1251236778 is a wasteful number, since it uses less digits than its factorization.

1251236778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95482.

The product of its digits is 141120, while the sum is 42.

The square root of 1251236778 is about 35372.8254172606. The cubic root of 1251236778 is about 1077.5725022318.

The spelling of 1251236778 in words is "one billion, two hundred fifty-one million, two hundred thirty-six thousand, seven hundred seventy-eight".