2181869937 has 18 divisors (see below), whose sum is σ = 3412670742. Its totient is φ = 1342688256.

The previous prime is 2181869933. The next prime is 2181869951. The reversal of 2181869937 is 7399681812.

It can be written as a sum of positive squares in 3 ways, for example, as 37161216 + 2144708721 = 6096^2 + 46311^2 .

It is not a de Polignac number, because 2181869937 - 2² = 2181869933 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2181869933) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 715728 + ... + 718769.

It is an arithmetic number, because the mean of its divisors is an integer number (189592819).

Almost surely, 2^2181869937 is an apocalyptic number.

It is an amenable number.

2181869937 is a deficient number, since it is larger than the sum of its proper divisors (1230800805).

2181869937 is a wasteful number, since it uses less digits than its factorization.

2181869937 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1434529 (or 1434513 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 54.

The square root of 2181869937 is about 46710.4906525290. The cubic root of 2181869937 is about 1297.0088898372.

The spelling of 2181869937 in words is "two billion, one hundred eighty-one million, eight hundred sixty-nine thousand, nine hundred thirty-seven".