1391990972 has 12 divisors (see below), whose sum is σ = 2463355440. Its totient is φ = 688175136.

The previous prime is 1391990947. The next prime is 1391991011. The reversal of 1391990972 is 2790991931.

It is a super-2 number, since 2×1391990972² = 3875277732259009568, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1391990972.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1954688 + ... + 1955399.

It is an arithmetic number, because the mean of its divisors is an integer number (205279620).

Almost surely, 2^1391990972 is an apocalyptic number.

It is an amenable number.

1391990972 is a deficient number, since it is larger than the sum of its proper divisors (1071364468).

1391990972 is a wasteful number, since it uses less digits than its factorization.

1391990972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3910180 (or 3910178 counting only the distinct ones).

The product of its (nonzero) digits is 275562, while the sum is 50.

The square root of 1391990972 is about 37309.3952242595. The cubic root of 1391990972 is about 1116.5516204735.

The spelling of 1391990972 in words is "one billion, three hundred ninety-one million, nine hundred ninety thousand, nine hundred seventy-two".