161640866 has 8 divisors (see below), whose sum is σ = 255222480. Its totient is φ = 76566708.

The previous prime is 161640863. The next prime is 161640883. The reversal of 161640866 is 668046161.

It is a happy number.

161640866 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×161640866² = 52255539122459912, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (38), and also a Moran number because the ratio is a prime number: 4253707 = 161640866 / (1 + 6 + 1 + 6 + 4 + 0 + 8 + 6 + 6).

It is not an unprimeable number, because it can be changed into a prime (161640863) 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, 2126816 + ... + 2126891.

It is an arithmetic number, because the mean of its divisors is an integer number (31902810).

Almost surely, 2^161640866 is an apocalyptic number.

161640866 is a deficient number, since it is larger than the sum of its proper divisors (93581614).

161640866 is a wasteful number, since it uses less digits than its factorization.

161640866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4253728.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 161640866 is about 12713.8061177603. The cubic root of 161640866 is about 544.7330466035.

The spelling of 161640866 in words is "one hundred sixty-one million, six hundred forty thousand, eight hundred sixty-six".