172867421 has 2 divisors, whose sum is σ = 172867422. Its totient is φ = 172867420.

The previous prime is 172867417. The next prime is 172867423. The reversal of 172867421 is 124768271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 89510521 + 83356900 = 9461^2 + 9130^2 .

It is a cyclic number.

It is not a de Polignac number, because 172867421 - 2² = 172867417 is a prime.

Together with 172867423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172867423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86433710 + 86433711.

It is an arithmetic number, because the mean of its divisors is an integer number (86433711).

Almost surely, 2^172867421 is an apocalyptic number.

It is an amenable number.

172867421 is a deficient number, since it is larger than the sum of its proper divisors (1).

172867421 is an equidigital number, since it uses as much as digits as its factorization.

172867421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 37632, while the sum is 38.

The square root of 172867421 is about 13147.9055746533. The cubic root of 172867421 is about 557.0630905589.

The spelling of 172867421 in words is "one hundred seventy-two million, eight hundred sixty-seven thousand, four hundred twenty-one".