20931943 has 2 divisors, whose sum is σ = 20931944. Its totient is φ = 20931942.

The previous prime is 20931941. The next prime is 20931949. The reversal of 20931943 is 34913902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20931943 - 2¹ = 20931941 is a prime.

Together with 20931941, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20931941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10465971 + 10465972.

It is an arithmetic number, because the mean of its divisors is an integer number (10465972).

Almost surely, 2^20931943 is an apocalyptic number.

20931943 is a deficient number, since it is larger than the sum of its proper divisors (1).

20931943 is an equidigital number, since it uses as much as digits as its factorization.

20931943 is an evil number, because the sum of its binary digits is even.

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

The square root of 20931943 is about 4575.1440414483. The cubic root of 20931943 is about 275.5940568372.

The spelling of 20931943 in words is "twenty million, nine hundred thirty-one thousand, nine hundred forty-three".