9961720 has 32 divisors (see below), whose sum is σ = 22510800. Its totient is φ = 3967488.

The previous prime is 9961687. The next prime is 9961723. The reversal of 9961720 is 271699.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9961723) 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, 13111 + ... + 13849.

Almost surely, 2^9961720 is an apocalyptic number.

It is an amenable number.

9961720 is an abundant number, since it is smaller than the sum of its proper divisors (12549080).

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

9961720 is a wasteful number, since it uses less digits than its factorization.

9961720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1087 (or 1083 counting only the distinct ones).

The product of its (nonzero) digits is 6804, while the sum is 34.

The square root of 9961720 is about 3156.2192572760. The cubic root of 9961720 is about 215.1682116090.

The spelling of 9961720 in words is "nine million, nine hundred sixty-one thousand, seven hundred twenty".