161221670630 has 16 divisors (see below), whose sum is σ = 290683490400. Its totient is φ = 64381005312.

The previous prime is 161221670609. The next prime is 161221670669. The reversal of 161221670630 is 36076122161.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13451579 + ... + 13463558.

It is an arithmetic number, because the mean of its divisors is an integer number (18167718150).

Almost surely, 2^161221670630 is an apocalyptic number.

161221670630 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161221670630 is a deficient number, since it is larger than the sum of its proper divisors (129461819770).

161221670630 is a wasteful number, since it uses less digits than its factorization.

161221670630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26915743.

The product of its (nonzero) digits is 18144, while the sum is 35.

Adding to 161221670630 its reverse (36076122161), we get a palindrome (197297792791).

The spelling of 161221670630 in words is "one hundred sixty-one billion, two hundred twenty-one million, six hundred seventy thousand, six hundred thirty".