172215420 has 48 divisors (see below), whose sum is σ = 519298080. Its totient is φ = 42391296.

The previous prime is 172215413. The next prime is 172215431. The reversal of 172215420 is 24512271.

172215420 = T₄₅₆ + T₄₅₇ + ... + T₁₀₄₀.

172215420 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, 109615 + ... + 111174.

It is an arithmetic number, because the mean of its divisors is an integer number (10818710).

Almost surely, 2^172215420 is an apocalyptic number.

172215420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

172215420 is an abundant number, since it is smaller than the sum of its proper divisors (347082660).

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

172215420 is a wasteful number, since it uses less digits than its factorization.

172215420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220814 (or 220812 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 24.

The square root of 172215420 is about 13123.0872892014. The cubic root of 172215420 is about 556.3618531957.

Adding to 172215420 its reverse (24512271), we get a palindrome (196727691).

The spelling of 172215420 in words is "one hundred seventy-two million, two hundred fifteen thousand, four hundred twenty".