9921620673 has 24 divisors (see below), whose sum is σ = 14428301472. Its totient is φ = 6569722368.

The previous prime is 9921620671. The next prime is 9921620677. The reversal of 9921620673 is 3760261299.

It is a happy number.

It is not a de Polignac number, because 9921620673 - 2¹ = 9921620671 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9921620671) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1182190 + ... + 1190552.

It is an arithmetic number, because the mean of its divisors is an integer number (601179228).

Almost surely, 2^9921620673 is an apocalyptic number.

It is an amenable number.

9921620673 is a deficient number, since it is larger than the sum of its proper divisors (4506680799).

9921620673 is a wasteful number, since it uses less digits than its factorization.

9921620673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9245 (or 9242 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 45.

The square root of 9921620673 is about 99607.3324258812. The cubic root of 9921620673 is about 2148.7911483135.

The spelling of 9921620673 in words is "nine billion, nine hundred twenty-one million, six hundred twenty thousand, six hundred seventy-three".