20943931 has 2 divisors, whose sum is σ = 20943932. Its totient is φ = 20943930.

The previous prime is 20943929. The next prime is 20943943. The reversal of 20943931 is 13934902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20943931 - 2¹ = 20943929 is a prime.

It is a super-2 number, since 2×20943931² = 877296491465522, which contains 22 as substring.

Together with 20943929, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 20943893 and 20943902.

It is not a weakly prime, because it can be changed into another prime (20943911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10471965 + 10471966.

It is an arithmetic number, because the mean of its divisors is an integer number (10471966).

Almost surely, 2^20943931 is an apocalyptic number.

20943931 is a deficient number, since it is larger than the sum of its proper divisors (1).

20943931 is an equidigital number, since it uses as much as digits as its factorization.

20943931 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 31.

The square root of 20943931 is about 4576.4539766068. The cubic root of 20943931 is about 275.6466589143.

The spelling of 20943931 in words is "twenty million, nine hundred forty-three thousand, nine hundred thirty-one".