9902421 has 24 divisors (see below), whose sum is σ = 14867424. Its totient is φ = 6346080.

The previous prime is 9902419. The next prime is 9902437. The reversal of 9902421 is 1242099.

9902421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9902421 - 2¹ = 9902419 is a prime.

It is a super-2 number, since 2×9902421² = 196115883322482, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9902411) 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, 43510 + ... + 43736.

It is an arithmetic number, because the mean of its divisors is an integer number (619476).

Almost surely, 2^9902421 is an apocalyptic number.

It is an amenable number.

9902421 is a deficient number, since it is larger than the sum of its proper divisors (4965003).

9902421 is a wasteful number, since it uses less digits than its factorization.

9902421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 401 (or 398 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 9902421 is about 3146.8112431476. The cubic root of 9902421 is about 214.7404186464.

The spelling of 9902421 in words is "nine million, nine hundred two thousand, four hundred twenty-one".