173971981 has 2 divisors, whose sum is σ = 173971982. Its totient is φ = 173971980.

The previous prime is 173971883. The next prime is 173971997. The reversal of 173971981 is 189179371.

173971981 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., 167469481 + 6502500 = 12941^2 + 2550^2 .

It is a cyclic number.

It is not a de Polignac number, because 173971981 - 2¹⁹ = 173447693 is a prime.

It is a super-2 number, since 2×173971981² = 60532500346128722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (173971381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86985990 + 86985991.

It is an arithmetic number, because the mean of its divisors is an integer number (86985991).

Almost surely, 2^173971981 is an apocalyptic number.

It is an amenable number.

173971981 is a deficient number, since it is larger than the sum of its proper divisors (1).

173971981 is an equidigital number, since it uses as much as digits as its factorization.

173971981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 95256, while the sum is 46.

The square root of 173971981 is about 13189.8438580599. The cubic root of 173971981 is about 558.2470493432.

The spelling of 173971981 in words is "one hundred seventy-three million, nine hundred seventy-one thousand, nine hundred eighty-one".