1391666975 has 6 divisors (see below), whose sum is σ = 1725667080. Its totient is φ = 1113333560.

The previous prime is 1391666959. The next prime is 1391666987. The reversal of 1391666975 is 5796661931.

It is not a de Polignac number, because 1391666975 - 2⁴ = 1391666959 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 27833315 + ... + 27833364.

It is an arithmetic number, because the mean of its divisors is an integer number (287611180).

Almost surely, 2^1391666975 is an apocalyptic number.

1391666975 is a deficient number, since it is larger than the sum of its proper divisors (334000105).

1391666975 is an equidigital number, since it uses as much as digits as its factorization.

1391666975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55666689 (or 55666684 counting only the distinct ones).

The product of its digits is 1837080, while the sum is 53.

The square root of 1391666975 is about 37305.0529419273. The cubic root of 1391666975 is about 1116.4649849867.

The spelling of 1391666975 in words is "one billion, three hundred ninety-one million, six hundred sixty-six thousand, nine hundred seventy-five".