2149231981 has 24 divisors (see below), whose sum is σ = 2361877056. Its totient is φ = 1954667520.

The previous prime is 2149231969. The next prime is 2149232011. The reversal of 2149231981 is 1891329412.

It is a happy number.

It is not a de Polignac number, because 2149231981 - 2³¹ = 1748333 is a prime.

It is a super-2 number, since 2×2149231981² = 9238396216306368722, 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 (2149231951) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4272576 + ... + 4273078.

It is an arithmetic number, because the mean of its divisors is an integer number (98411544).

Almost surely, 2^2149231981 is an apocalyptic number.

It is an amenable number.

2149231981 is a deficient number, since it is larger than the sum of its proper divisors (212645075).

2149231981 is a wasteful number, since it uses less digits than its factorization.

2149231981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 853 (or 840 counting only the distinct ones).

The product of its digits is 31104, while the sum is 40.

The square root of 2149231981 is about 46359.8099758832. The cubic root of 2149231981 is about 1290.5091796400.

The spelling of 2149231981 in words is "two billion, one hundred forty-nine million, two hundred thirty-one thousand, nine hundred eighty-one".