221742172 has 48 divisors (see below), whose sum is σ = 415179072. Its totient is φ = 103403520.

The previous prime is 221742161. The next prime is 221742181. The reversal of 221742172 is 271247122.

221742172 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 221742172.

It is a congruent number.

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, 919972 + ... + 920212.

It is an arithmetic number, because the mean of its divisors is an integer number (8649564).

Almost surely, 2^221742172 is an apocalyptic number.

It is an amenable number.

221742172 is a deficient number, since it is larger than the sum of its proper divisors (193436900).

221742172 is a wasteful number, since it uses less digits than its factorization.

221742172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478 (or 476 counting only the distinct ones).

The product of its digits is 3136, while the sum is 28.

The square root of 221742172 is about 14891.0097709994. The cubic root of 221742172 is about 605.2703952636.

Adding to 221742172 its reverse (271247122), we get a palindrome (492989294).

The spelling of 221742172 in words is "two hundred twenty-one million, seven hundred forty-two thousand, one hundred seventy-two".