172942991 has 8 divisors (see below), whose sum is σ = 189300384. Its totient is φ = 157021920.

The previous prime is 172942963. The next prime is 172942993. The reversal of 172942991 is 199249271.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 172942991 - 2¹⁸ = 172680847 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172942993) 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, 108251 + ... + 109836.

It is an arithmetic number, because the mean of its divisors is an integer number (23662548).

Almost surely, 2^172942991 is an apocalyptic number.

172942991 is a deficient number, since it is larger than the sum of its proper divisors (16357393).

172942991 is a wasteful number, since it uses less digits than its factorization.

172942991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218161.

The product of its digits is 81648, while the sum is 44.

The square root of 172942991 is about 13150.7791023954. The cubic root of 172942991 is about 557.1442531915.

The spelling of 172942991 in words is "one hundred seventy-two million, nine hundred forty-two thousand, nine hundred ninety-one".