166517961 has 4 divisors (see below), whose sum is σ = 222023952. Its totient is φ = 111011972.

The previous prime is 166517959. The next prime is 166517963. The reversal of 166517961 is 169715661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (166517959) and next prime (166517963).

It is a cyclic number.

It is not a de Polignac number, because 166517961 - 2¹ = 166517959 is a prime.

It is not an unprimeable number, because it can be changed into a prime (166517963) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27752991 + ... + 27752996.

It is an arithmetic number, because the mean of its divisors is an integer number (55505988).

Almost surely, 2^166517961 is an apocalyptic number.

It is an amenable number.

166517961 is a deficient number, since it is larger than the sum of its proper divisors (55505991).

166517961 is an equidigital number, since it uses as much as digits as its factorization.

166517961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55505990.

The product of its digits is 68040, while the sum is 42.

The square root of 166517961 is about 12904.1838564087. The cubic root of 166517961 is about 550.1574876828.

The spelling of 166517961 in words is "one hundred sixty-six million, five hundred seventeen thousand, nine hundred sixty-one".