1391947371 has 12 divisors (see below), whose sum is σ = 2012931648. Its totient is φ = 926884464.

The previous prime is 1391947351. The next prime is 1391947387. The reversal of 1391947371 is 1737491931.

It is not a de Polignac number, because 1391947371 - 2¹¹ = 1391945323 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1391947351) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 81840 + ... + 97373.

It is an arithmetic number, because the mean of its divisors is an integer number (167744304).

Almost surely, 2^1391947371 is an apocalyptic number.

1391947371 is a deficient number, since it is larger than the sum of its proper divisors (620984277).

1391947371 is a wasteful number, since it uses less digits than its factorization.

1391947371 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180082 (or 180079 counting only the distinct ones).

The product of its digits is 142884, while the sum is 45.

The square root of 1391947371 is about 37308.8109030561. The cubic root of 1391947371 is about 1116.5399625254.

The spelling of 1391947371 in words is "one billion, three hundred ninety-one million, nine hundred forty-seven thousand, three hundred seventy-one".