20905711 has 2 divisors, whose sum is σ = 20905712. Its totient is φ = 20905710.

The previous prime is 20905679. The next prime is 20905727. The reversal of 20905711 is 11750902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20905711 - 2⁵ = 20905679 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20905751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10452855 + 10452856.

It is an arithmetic number, because the mean of its divisors is an integer number (10452856).

Almost surely, 2^20905711 is an apocalyptic number.

20905711 is a deficient number, since it is larger than the sum of its proper divisors (1).

20905711 is an equidigital number, since it uses as much as digits as its factorization.

20905711 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 630, while the sum is 25.

The square root of 20905711 is about 4572.2763477288. The cubic root of 20905711 is about 275.4788834972.

The spelling of 20905711 in words is "twenty million, nine hundred five thousand, seven hundred eleven".