172354921 has 4 divisors (see below), whose sum is σ = 172495492. Its totient is φ = 172214352.

The previous prime is 172354901. The next prime is 172354927. The reversal of 172354921 is 129453271.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 129453271 = 79 ⋅1638649.

It can be written as a sum of positive squares in 2 ways, for example, as 69555600 + 102799321 = 8340^2 + 10139^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-172354921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172354927) 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, 68430 + ... + 70903.

It is an arithmetic number, because the mean of its divisors is an integer number (43123873).

Almost surely, 2^172354921 is an apocalyptic number.

It is an amenable number.

172354921 is a deficient number, since it is larger than the sum of its proper divisors (140571).

172354921 is a wasteful number, since it uses less digits than its factorization.

172354921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140570.

The product of its digits is 15120, while the sum is 34.

The square root of 172354921 is about 13128.4013116602. The cubic root of 172354921 is about 556.5120373619.

It can be divided in two parts, 1723 and 54921, that added together give a square (56644 = 238²).

The spelling of 172354921 in words is "one hundred seventy-two million, three hundred fifty-four thousand, nine hundred twenty-one".