161720630 has 16 divisors (see below), whose sum is σ = 291481200. Its totient is φ = 64602912.

The previous prime is 161720627. The next prime is 161720639. The reversal of 161720630 is 36027161.

161720630 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 161720630.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161720639) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2405 + ... + 18144.

It is an arithmetic number, because the mean of its divisors is an integer number (18217575).

Almost surely, 2^161720630 is an apocalyptic number.

161720630 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161720630 is a deficient number, since it is larger than the sum of its proper divisors (129760570).

161720630 is a wasteful number, since it uses less digits than its factorization.

161720630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21343.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 161720630 is about 12716.9426357124. The cubic root of 161720630 is about 544.8226339765.

Adding to 161720630 its reverse (36027161), we get a palindrome (197747791).

The spelling of 161720630 in words is "one hundred sixty-one million, seven hundred twenty thousand, six hundred thirty".