1251666916 has 6 divisors (see below), whose sum is σ = 2190417110. Its totient is φ = 625833456.

The previous prime is 1251666859. The next prime is 1251666931. The reversal of 1251666916 is 6196661521.

It can be written as a sum of positive squares in only one way, i.e., 894608100 + 357058816 = 29910^2 + 18896^2 .

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 as a sum of consecutive naturals, namely, 156458361 + ... + 156458368.

Almost surely, 2^1251666916 is an apocalyptic number.

It is an amenable number.

1251666916 is a deficient number, since it is larger than the sum of its proper divisors (938750194).

1251666916 is a wasteful number, since it uses less digits than its factorization.

1251666916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312916733 (or 312916731 counting only the distinct ones).

The product of its digits is 116640, while the sum is 43.

The square root of 1251666916 is about 35378.9049576156. The cubic root of 1251666916 is about 1077.6959672136.

The spelling of 1251666916 in words is "one billion, two hundred fifty-one million, six hundred sixty-six thousand, nine hundred sixteen".