172920730397 has 4 divisors (see below), whose sum is σ = 173223569376. Its totient is φ = 172617891420.

The previous prime is 172920730369. The next prime is 172920730399. The reversal of 172920730397 is 793037029271.

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-172920730397 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 (172920730399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 151418633 + ... + 151419774.

It is an arithmetic number, because the mean of its divisors is an integer number (43305892344).

Almost surely, 2^172920730397 is an apocalyptic number.

It is an amenable number.

172920730397 is a deficient number, since it is larger than the sum of its proper divisors (302838979).

172920730397 is an equidigital number, since it uses as much as digits as its factorization.

172920730397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302838978.

The product of its (nonzero) digits is 1000188, while the sum is 50.

The spelling of 172920730397 in words is "one hundred seventy-two billion, nine hundred twenty million, seven hundred thirty thousand, three hundred ninety-seven".