2161221612 has 48 divisors (see below), whose sum is σ = 5504951424. Its totient is φ = 654480000.

The previous prime is 2161221599. The next prime is 2161221641.

2161221612 is nontrivially palindromic in base 10.

2161221612 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 233187 + ... + 242277.

It is an arithmetic number, because the mean of its divisors is an integer number (114686488).

Almost surely, 2^2161221612 is an apocalyptic number.

2161221612 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

2161221612 is an abundant number, since it is smaller than the sum of its proper divisors (3343729812).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2161221612 is a wasteful number, since it uses less digits than its factorization.

2161221612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10910 (or 10908 counting only the distinct ones).

The product of its digits is 576, while the sum is 24.

The square root of 2161221612 is about 46488.9407493868. The cubic root of 2161221612 is about 1292.9044609879.

The spelling of 2161221612 in words is "two billion, one hundred sixty-one million, two hundred twenty-one thousand, six hundred twelve".