2151581944 has 16 divisors (see below), whose sum is σ = 4035529800. Its totient is φ = 1075440672.

The previous prime is 2151581923. The next prime is 2151581963. The reversal of 2151581944 is 4491851512.

It is a junction number, because it is equal to n+sod(n) for n = 2151581897 and 2151581906.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16699 + ... + 67690.

Almost surely, 2^2151581944 is an apocalyptic number.

It is an amenable number.

2151581944 is a deficient number, since it is larger than the sum of its proper divisors (1883947856).

2151581944 is a wasteful number, since it uses less digits than its factorization.

2151581944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87582 (or 87578 counting only the distinct ones).

The product of its digits is 57600, while the sum is 40.

The square root of 2151581944 is about 46385.1478816226. The cubic root of 2151581944 is about 1290.9793544474.

The spelling of 2151581944 in words is "two billion, one hundred fifty-one million, five hundred eighty-one thousand, nine hundred forty-four".