1661601166 has 4 divisors (see below), whose sum is σ = 2492401752. Its totient is φ = 830800582.

The previous prime is 1661601119. The next prime is 1661601191. The reversal of 1661601166 is 6611061661.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 415400290 + ... + 415400293.

It is an arithmetic number, because the mean of its divisors is an integer number (623100438).

Almost surely, 2^1661601166 is an apocalyptic number.

1661601166 is a deficient number, since it is larger than the sum of its proper divisors (830800586).

1661601166 is an equidigital number, since it uses as much as digits as its factorization.

1661601166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 830800585.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 1661601166 is about 40762.7423758510. The cubic root of 1661601166 is about 1184.4287195123.

The spelling of 1661601166 in words is "one billion, six hundred sixty-one million, six hundred one thousand, one hundred sixty-six".