961555020 has 144 divisors (see below), whose sum is σ = 2985631488. Its totient is φ = 230743040.

The previous prime is 961554977. The next prime is 961555031. The reversal of 961555020 is 20555169.

It is a super-3 number, since 3×961555020³ (a number of 28 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 397615 + ... + 400025.

It is an arithmetic number, because the mean of its divisors is an integer number (20733552).

Almost surely, 2^961555020 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 961555020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1492815744).

961555020 is an abundant number, since it is smaller than the sum of its proper divisors (2024076468).

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

961555020 is a wasteful number, since it uses less digits than its factorization.

961555020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2480 (or 2461 counting only the distinct ones).

The product of its (nonzero) digits is 13500, while the sum is 33.

The square root of 961555020 is about 31008.9506433223. The cubic root of 961555020 is about 987.0171825511.

The spelling of 961555020 in words is "nine hundred sixty-one million, five hundred fifty-five thousand, twenty".