21942331 has 4 divisors (see below), whose sum is σ = 22102632. Its totient is φ = 21782032.

The previous prime is 21942317. The next prime is 21942377. The reversal of 21942331 is 13324912.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21942331 - 2²¹ = 19845179 is a prime.

It is a super-2 number, since 2×21942331² = 962931779427122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21942296 and 21942305.

It is not an unprimeable number, because it can be changed into a prime (21942731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79945 + ... + 80218.

It is an arithmetic number, because the mean of its divisors is an integer number (5525658).

Almost surely, 2^21942331 is an apocalyptic number.

21942331 is a deficient number, since it is larger than the sum of its proper divisors (160301).

21942331 is a wasteful number, since it uses less digits than its factorization.

21942331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160300.

The product of its digits is 1296, while the sum is 25.

The square root of 21942331 is about 4684.2641898168. The cubic root of 21942331 is about 279.9588842689.

The spelling of 21942331 in words is "twenty-one million, nine hundred forty-two thousand, three hundred thirty-one".