961720320 has 208 divisors, whose sum is σ = 3359227392. Its totient is φ = 232980480.

The previous prime is 961720307. The next prime is 961720343. The reversal of 961720320 is 23027169.

It is a Harshad number since it is a multiple of its sum of digits (30).

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, 675129 + ... + 676551.

Almost surely, 2^961720320 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 961720320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1679613696).

961720320 is an abundant number, since it is smaller than the sum of its proper divisors (2397507072).

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

961720320 is a wasteful number, since it uses less digits than its factorization.

961720320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1466 (or 1444 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 961720320 is about 31011.6158882442. The cubic root of 961720320 is about 987.0737383690.

Adding to 961720320 its reverse (23027169), we get a palindrome (984747489).

The spelling of 961720320 in words is "nine hundred sixty-one million, seven hundred twenty thousand, three hundred twenty".