172391749 has 4 divisors (see below), whose sum is σ = 174098700. Its totient is φ = 170684800.

The previous prime is 172391741. The next prime is 172391753. The reversal of 172391749 is 947193271.

It is a happy number.

172391749 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 133864900 + 38526849 = 11570^2 + 6207^2 .

It is a cyclic number.

It is not a de Polignac number, because 172391749 - 2³ = 172391741 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 (172391741) 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, 853324 + ... + 853525.

It is an arithmetic number, because the mean of its divisors is an integer number (43524675).

Almost surely, 2^172391749 is an apocalyptic number.

It is an amenable number.

172391749 is a deficient number, since it is larger than the sum of its proper divisors (1706951).

172391749 is a wasteful number, since it uses less digits than its factorization.

172391749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1706950.

The product of its digits is 95256, while the sum is 43.

The square root of 172391749 is about 13129.8038446886. The cubic root of 172391749 is about 556.5516721759.

The spelling of 172391749 in words is "one hundred seventy-two million, three hundred ninety-one thousand, seven hundred forty-nine".