172221731712 has 64 divisors (see below), whose sum is σ = 508293315600. Its totient is φ = 57407242752.

The previous prime is 172221731707. The next prime is 172221731719. The reversal of 172221731712 is 217137122271.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172221731719) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24912883 + ... + 24919794.

Almost surely, 2^172221731712 is an apocalyptic number.

172221731712 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

172221731712 is an abundant number, since it is smaller than the sum of its proper divisors (336071583888).

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

172221731712 is an equidigital number, since it uses as much as digits as its factorization.

172221731712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49832700 (or 49832682 counting only the distinct ones).

The product of its digits is 16464, while the sum is 36.

Adding to 172221731712 its reverse (217137122271), we get a palindrome (389358853983).

The spelling of 172221731712 in words is "one hundred seventy-two billion, two hundred twenty-one million, seven hundred thirty-one thousand, seven hundred twelve".