9942521 has 4 divisors (see below), whose sum is σ = 10154112. Its totient is φ = 9730932.

The previous prime is 9942497. The next prime is 9942523. The reversal of 9942521 is 1252499.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1252499 = 19 ⋅65921.

It is a cyclic number.

It is not a de Polignac number, because 9942521 - 2²² = 5748217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9942523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105725 + ... + 105818.

It is an arithmetic number, because the mean of its divisors is an integer number (2538528).

Almost surely, 2^9942521 is an apocalyptic number.

It is an amenable number.

9942521 is a deficient number, since it is larger than the sum of its proper divisors (211591).

9942521 is a wasteful number, since it uses less digits than its factorization.

9942521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211590.

The product of its digits is 6480, while the sum is 32.

The square root of 9942521 is about 3153.1763350628. The cubic root of 9942521 is about 215.0298930853.

The spelling of 9942521 in words is "nine million, nine hundred forty-two thousand, five hundred twenty-one".