161221024 has 12 divisors (see below), whose sum is σ = 317403954. Its totient is φ = 80610496.

The previous prime is 161221003. The next prime is 161221069. The reversal of 161221024 is 420122161.

It can be written as a sum of positive squares in only one way, i.e., 126787600 + 34433424 = 11260^2 + 5868^2 .

It is a junction number, because it is equal to n+sod(n) for n = 161220992 and 161221010.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2519047 + ... + 2519110.

Almost surely, 2^161221024 is an apocalyptic number.

It is an amenable number.

161221024 is a deficient number, since it is larger than the sum of its proper divisors (156182930).

161221024 is an equidigital number, since it uses as much as digits as its factorization.

161221024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5038167 (or 5038159 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 161221024 is about 12697.2841190548. The cubic root of 161221024 is about 544.2610122890.

Adding to 161221024 its reverse (420122161), we get a palindrome (581343185).

The spelling of 161221024 in words is "one hundred sixty-one million, two hundred twenty-one thousand, twenty-four".