2149172861 has 32 divisors (see below), whose sum is σ = 2637722880. Its totient is φ = 1727308800.

The previous prime is 2149172833. The next prime is 2149172863. The reversal of 2149172861 is 1682719412.

It is not a de Polignac number, because 2149172861 - 2⁶ = 2149172797 is a prime.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2149172863) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 195296 + ... + 206006.

It is an arithmetic number, because the mean of its divisors is an integer number (82428840).

Almost surely, 2^2149172861 is an apocalyptic number.

It is an amenable number.

2149172861 is a deficient number, since it is larger than the sum of its proper divisors (488550019).

2149172861 is a wasteful number, since it uses less digits than its factorization.

2149172861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10805.

The product of its digits is 48384, while the sum is 41.

The square root of 2149172861 is about 46359.1723502480. The cubic root of 2149172861 is about 1290.4973466375.

The spelling of 2149172861 in words is "two billion, one hundred forty-nine million, one hundred seventy-two thousand, eight hundred sixty-one".