9921501 has 16 divisors (see below), whose sum is σ = 14750400. Its totient is φ = 6591024.

The previous prime is 9921491. The next prime is 9921521. The reversal of 9921501 is 1051299.

It is a happy number.

It is not a de Polignac number, because 9921501 - 2¹⁵ = 9888733 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9921521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10875 + ... + 11751.

It is an arithmetic number, because the mean of its divisors is an integer number (921900).

Almost surely, 2^9921501 is an apocalyptic number.

It is an amenable number.

9921501 is a deficient number, since it is larger than the sum of its proper divisors (4828899).

9921501 is a wasteful number, since it uses less digits than its factorization.

9921501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1305 (or 1299 counting only the distinct ones).

The product of its (nonzero) digits is 810, while the sum is 27.

The square root of 9921501 is about 3149.8414245800. The cubic root of 9921501 is about 214.8782508820.

The spelling of 9921501 in words is "nine million, nine hundred twenty-one thousand, five hundred one".