173506661 has 2 divisors, whose sum is σ = 173506662. Its totient is φ = 173506660.

The previous prime is 173506649. The next prime is 173506667. The reversal of 173506661 is 166605371.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 173422561 + 84100 = 13169^2 + 290^2 .

It is a cyclic number.

It is not a de Polignac number, because 173506661 - 2¹⁴ = 173490277 is a prime.

It is a super-2 number, since 2×173506661² = 60209122822737842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (173506667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86753330 + 86753331.

It is an arithmetic number, because the mean of its divisors is an integer number (86753331).

Almost surely, 2^173506661 is an apocalyptic number.

It is an amenable number.

173506661 is a deficient number, since it is larger than the sum of its proper divisors (1).

173506661 is an equidigital number, since it uses as much as digits as its factorization.

173506661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 35.

The square root of 173506661 is about 13172.1927179950. The cubic root of 173506661 is about 557.7488935380.

The spelling of 173506661 in words is "one hundred seventy-three million, five hundred six thousand, six hundred sixty-one".