172997939 has 4 divisors (see below), whose sum is σ = 173511624. Its totient is φ = 172484256.

The previous prime is 172997893. The next prime is 172997941. The reversal of 172997939 is 939799271.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 172997939 - 2²⁰ = 171949363 is a prime.

It is a super-3 number, since 3×172997939³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172997969) 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, 256337 + ... + 257010.

It is an arithmetic number, because the mean of its divisors is an integer number (43377906).

Almost surely, 2^172997939 is an apocalyptic number.

172997939 is a deficient number, since it is larger than the sum of its proper divisors (513685).

172997939 is an equidigital number, since it uses as much as digits as its factorization.

172997939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513684.

The product of its digits is 1928934, while the sum is 56.

The square root of 172997939 is about 13152.8680902684. The cubic root of 172997939 is about 557.2032528278.

The spelling of 172997939 in words is "one hundred seventy-two million, nine hundred ninety-seven thousand, nine hundred thirty-nine".