161217770 has 32 divisors (see below), whose sum is σ = 334198656. Its totient is φ = 54849600.

The previous prime is 161217761. The next prime is 161217773. The reversal of 161217770 is 77712161.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (161217773) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 380 + ... + 17960.

It is an arithmetic number, because the mean of its divisors is an integer number (10443708).

Almost surely, 2^161217770 is an apocalyptic number.

161217770 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161217770 is an abundant number, since it is smaller than the sum of its proper divisors (172980886).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161217770 is a wasteful number, since it uses less digits than its factorization.

161217770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17726.

The product of its (nonzero) digits is 4116, while the sum is 32.

The square root of 161217770 is about 12697.1559807699. The cubic root of 161217770 is about 544.2573505721.

The spelling of 161217770 in words is "one hundred sixty-one million, two hundred seventeen thousand, seven hundred seventy".