3891392981 has 16 divisors (see below), whose sum is σ = 4522598400. Its totient is φ = 3279367728.

The previous prime is 3891392963. The next prime is 3891392993. The reversal of 3891392981 is 1892931983.

It is not a de Polignac number, because 3891392981 - 2²⁶ = 3824284117 is a prime.

It is a super-2 number, since 2×3891392981² = 30285878665152132722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3891392951) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117446 + ... + 146888.

It is an arithmetic number, because the mean of its divisors is an integer number (282662400).

Almost surely, 2^3891392981 is an apocalyptic number.

It is an amenable number.

3891392981 is a deficient number, since it is larger than the sum of its proper divisors (631205419).

3891392981 is a wasteful number, since it uses less digits than its factorization.

3891392981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29768.

The product of its digits is 839808, while the sum is 53.

The square root of 3891392981 is about 62381.0306182897. The cubic root of 3891392981 is about 1572.9021174075.

The spelling of 3891392981 in words is "three billion, eight hundred ninety-one million, three hundred ninety-two thousand, nine hundred eighty-one".