172661213 has 4 divisors (see below), whose sum is σ = 173903520. Its totient is φ = 171418908.

The previous prime is 172661201. The next prime is 172661219. The reversal of 172661213 is 312166271.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-172661213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172661219) 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, 620945 + ... + 621222.

It is an arithmetic number, because the mean of its divisors is an integer number (43475880).

Almost surely, 2^172661213 is an apocalyptic number.

It is an amenable number.

172661213 is a deficient number, since it is larger than the sum of its proper divisors (1242307).

172661213 is a wasteful number, since it uses less digits than its factorization.

172661213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1242306.

The product of its digits is 3024, while the sum is 29.

The square root of 172661213 is about 13140.0613773300. The cubic root of 172661213 is about 556.8415015310.

The spelling of 172661213 in words is "one hundred seventy-two million, six hundred sixty-one thousand, two hundred thirteen".