2819181921 has 16 divisors (see below), whose sum is σ = 3935145984. Its totient is φ = 1791869904.

The previous prime is 2819181919. The next prime is 2819181931. The reversal of 2819181921 is 1291819182.

It is a happy number.

It is not a de Polignac number, because 2819181921 - 2¹ = 2819181919 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2819181931) 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, 45361 + ... + 87726.

It is an arithmetic number, because the mean of its divisors is an integer number (245946624).

Almost surely, 2^2819181921 is an apocalyptic number.

It is an amenable number.

2819181921 is a deficient number, since it is larger than the sum of its proper divisors (1115964063).

2819181921 is a wasteful number, since it uses less digits than its factorization.

2819181921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133420.

The product of its digits is 20736, while the sum is 42.

The square root of 2819181921 is about 53095.9689712882. The cubic root of 2819181921 is about 1412.6710131629.

The spelling of 2819181921 in words is "two billion, eight hundred nineteen million, one hundred eighty-one thousand, nine hundred twenty-one".