1331981957 has 8 divisors (see below), whose sum is σ = 1391069184. Its totient is φ = 1272992688.

The previous prime is 1331981953. The next prime is 1331981971. The reversal of 1331981957 is 7591891331.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1331981957 - 2² = 1331981953 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1331981953) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4028 + ... + 51770.

It is an arithmetic number, because the mean of its divisors is an integer number (173883648).

Almost surely, 2^1331981957 is an apocalyptic number.

It is an amenable number.

1331981957 is a deficient number, since it is larger than the sum of its proper divisors (59087227).

1331981957 is a wasteful number, since it uses less digits than its factorization.

1331981957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48979.

The product of its digits is 204120, while the sum is 47.

The square root of 1331981957 is about 36496.3279933749. The cubic root of 1331981957 is about 1100.2704450734.

The spelling of 1331981957 in words is "one billion, three hundred thirty-one million, nine hundred eighty-one thousand, nine hundred fifty-seven".