9961497820 has 48 divisors (see below), whose sum is σ = 22664825568. Its totient is φ = 3662991360.

The previous prime is 9961497781. The next prime is 9961497839. The reversal of 9961497820 is 287941699.

It is a congruent number.

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, 326061 + ... + 355300.

It is an arithmetic number, because the mean of its divisors is an integer number (472183866).

Almost surely, 2^9961497820 is an apocalyptic number.

It is an amenable number.

9961497820 is an abundant number, since it is smaller than the sum of its proper divisors (12703327748).

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

9961497820 is a wasteful number, since it uses less digits than its factorization.

9961497820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 681430 (or 681428 counting only the distinct ones).

The product of its (nonzero) digits is 1959552, while the sum is 55.

The square root of 9961497820 is about 99807.3034401792. The cubic root of 9961497820 is about 2151.6661193779. Note that the first 3 decimals are identical.

The spelling of 9961497820 in words is "nine billion, nine hundred sixty-one million, four hundred ninety-seven thousand, eight hundred twenty".