173072021 has 2 divisors, whose sum is σ = 173072022. Its totient is φ = 173072020.

The previous prime is 173071991. The next prime is 173072023. The reversal of 173072021 is 120270371.

173072021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 139594225 + 33477796 = 11815^2 + 5786^2 .

It is a cyclic number.

It is not a de Polignac number, because 173072021 - 2¹⁴ = 173055637 is a prime.

Together with 173072023, 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 (173072023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86536010 + 86536011.

It is an arithmetic number, because the mean of its divisors is an integer number (86536011).

Almost surely, 2^173072021 is an apocalyptic number.

It is an amenable number.

173072021 is a deficient number, since it is larger than the sum of its proper divisors (1).

173072021 is an equidigital number, since it uses as much as digits as its factorization.

173072021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 588, while the sum is 23.

The square root of 173072021 is about 13155.6839806982. The cubic root of 173072021 is about 557.2827775528.

The spelling of 173072021 in words is "one hundred seventy-three million, seventy-two thousand, twenty-one".