1391961252 has 72 divisors (see below), whose sum is σ = 3607185568. Its totient is φ = 417415680.

The previous prime is 1391961239. The next prime is 1391961301. The reversal of 1391961252 is 2521691931.

It is a super-2 number, since 2×1391961252² = 3875112254138815008, 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 1391961252.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 135903 + ... + 145785.

Almost surely, 2^1391961252 is an apocalyptic number.

1391961252 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1391961252, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1803592784).

1391961252 is an abundant number, since it is smaller than the sum of its proper divisors (2215224316).

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

1391961252 is a wasteful number, since it uses less digits than its factorization.

1391961252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10009 (or 9996 counting only the distinct ones).

The product of its digits is 29160, while the sum is 39.

The square root of 1391961252 is about 37308.9969310353. The cubic root of 1391961252 is about 1116.5436740259.

The spelling of 1391961252 in words is "one billion, three hundred ninety-one million, nine hundred sixty-one thousand, two hundred fifty-two".