2172446621 has 4 divisors (see below), whose sum is σ = 2174600700. Its totient is φ = 2170292544.

The previous prime is 2172446603. The next prime is 2172446641. The reversal of 2172446621 is 1266442712.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1525761721 + 646684900 = 39061^2 + 25430^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2172446621 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2172446641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1075526 + ... + 1077543.

It is an arithmetic number, because the mean of its divisors is an integer number (543650175).

Almost surely, 2^2172446621 is an apocalyptic number.

It is an amenable number.

2172446621 is a deficient number, since it is larger than the sum of its proper divisors (2154079).

2172446621 is a wasteful number, since it uses less digits than its factorization.

2172446621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2154078.

The product of its digits is 32256, while the sum is 35.

The square root of 2172446621 is about 46609.5121300363. The cubic root of 2172446621 is about 1295.1389704918.

The spelling of 2172446621 in words is "two billion, one hundred seventy-two million, four hundred forty-six thousand, six hundred twenty-one".