9921770408 has 32 divisors (see below), whose sum is σ = 20319219360. Its totient is φ = 4504409280.

The previous prime is 9921770393. The next prime is 9921770437. The reversal of 9921770408 is 8040771299.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4610 + ... + 140942.

It is an arithmetic number, because the mean of its divisors is an integer number (634975605).

Almost surely, 2^9921770408 is an apocalyptic number.

It is an amenable number.

9921770408 is an abundant number, since it is smaller than the sum of its proper divisors (10397448952).

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

9921770408 is a wasteful number, since it uses less digits than its factorization.

9921770408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137177 (or 137173 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 47.

The square root of 9921770408 is about 99608.0840494385. The cubic root of 9921770408 is about 2148.8019579595.

The spelling of 9921770408 in words is "nine billion, nine hundred twenty-one million, seven hundred seventy thousand, four hundred eight".