172038421 has 2 divisors, whose sum is σ = 172038422. Its totient is φ = 172038420.

The previous prime is 172038401. The next prime is 172038431. The reversal of 172038421 is 124830271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 166771396 + 5267025 = 12914^2 + 2295^2 .

It is a cyclic number.

It is not a de Polignac number, because 172038421 - 2⁵ = 172038389 is a prime.

It is a Chen prime.

It is equal to p_9610732 and since 172038421 and 9610732 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 172038421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172038401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86019210 + 86019211.

It is an arithmetic number, because the mean of its divisors is an integer number (86019211).

Almost surely, 2^172038421 is an apocalyptic number.

It is an amenable number.

172038421 is a deficient number, since it is larger than the sum of its proper divisors (1).

172038421 is an equidigital number, since it uses as much as digits as its factorization.

172038421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 172038421 is about 13116.3417537056. The cubic root of 172038421 is about 556.1711826044.

Adding to 172038421 its reverse (124830271), we get a palindrome (296868692).

The spelling of 172038421 in words is "one hundred seventy-two million, thirty-eight thousand, four hundred twenty-one".