21946331 has 4 divisors (see below), whose sum is σ = 23941464. Its totient is φ = 19951200.

The previous prime is 21946271. The next prime is 21946333. The reversal of 21946331 is 13364912.

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 21946331 - 2¹⁰ = 21945307 is a prime.

It is a super-2 number, since 2×21946331² = 963282888723122, 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 = 21946294 and 21946303.

It is not an unprimeable number, because it can be changed into a prime (21946333) 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, 997550 + ... + 997571.

It is an arithmetic number, because the mean of its divisors is an integer number (5985366).

Almost surely, 2^21946331 is an apocalyptic number.

21946331 is a deficient number, since it is larger than the sum of its proper divisors (1995133).

21946331 is a wasteful number, since it uses less digits than its factorization.

21946331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1995132.

The product of its digits is 3888, while the sum is 29.

The square root of 21946331 is about 4684.6911317610. The cubic root of 21946331 is about 279.9758950337.

The spelling of 21946331 in words is "twenty-one million, nine hundred forty-six thousand, three hundred thirty-one".