161561066 has 32 divisors (see below), whose sum is σ = 262906560. Its totient is φ = 74221056.

The previous prime is 161561051. The next prime is 161561087. The reversal of 161561066 is 660165161.

161561066 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×161561066² = 52203956094112712, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 194945 + ... + 195771.

It is an arithmetic number, because the mean of its divisors is an integer number (8215830).

Almost surely, 2^161561066 is an apocalyptic number.

161561066 is a deficient number, since it is larger than the sum of its proper divisors (101345494).

161561066 is a wasteful number, since it uses less digits than its factorization.

161561066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 998.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 161561066 is about 12710.6674096996. The cubic root of 161561066 is about 544.6433892999.

The spelling of 161561066 in words is "one hundred sixty-one million, five hundred sixty-one thousand, sixty-six".