2179989945 has 48 divisors (see below), whose sum is σ = 4347532800. Its totient is φ = 989857152.

The previous prime is 2179989923. The next prime is 2179989949. The reversal of 2179989945 is 5499899712.

It is not a de Polignac number, because 2179989945 - 2⁵ = 2179989913 is a prime.

It is a super-2 number, since 2×2179989945² = 9504712320602206050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2179989949) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 23712 + ... + 70158.

It is an arithmetic number, because the mean of its divisors is an integer number (90573600).

Almost surely, 2^2179989945 is an apocalyptic number.

It is an amenable number.

2179989945 is a deficient number, since it is larger than the sum of its proper divisors (2167542855).

2179989945 is a wasteful number, since it uses less digits than its factorization.

2179989945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46614 (or 46611 counting only the distinct ones).

The product of its digits is 14696640, while the sum is 63.

The square root of 2179989945 is about 46690.3624423713. The cubic root of 2179989945 is about 1296.6362634394.

The spelling of 2179989945 in words is "two billion, one hundred seventy-nine million, nine hundred eighty-nine thousand, nine hundred forty-five".