9965390820 has 384 divisors, whose sum is σ = 38032146432. Its totient is φ = 1885593600.

The previous prime is 9965390791. The next prime is 9965390863. The reversal of 9965390820 is 280935699.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2432694 + ... + 2436786.

It is an arithmetic number, because the mean of its divisors is an integer number (99042048).

Almost surely, 2^9965390820 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 9965390820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19016073216).

9965390820 is an abundant number, since it is smaller than the sum of its proper divisors (28066755612).

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

9965390820 is a wasteful number, since it uses less digits than its factorization.

9965390820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4171 (or 4169 counting only the distinct ones).

The product of its (nonzero) digits is 1049760, while the sum is 51.

The square root of 9965390820 is about 99826.8041159287. The cubic root of 9965390820 is about 2151.9463766045.

The spelling of 9965390820 in words is "nine billion, nine hundred sixty-five million, three hundred ninety thousand, eight hundred twenty".