20439911 has 2 divisors, whose sum is σ = 20439912. Its totient is φ = 20439910.

The previous prime is 20439871. The next prime is 20439917. The reversal of 20439911 is 11993402.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20439911 - 2¹⁴ = 20423527 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20439917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10219955 + 10219956.

It is an arithmetic number, because the mean of its divisors is an integer number (10219956).

Almost surely, 2^20439911 is an apocalyptic number.

20439911 is a deficient number, since it is larger than the sum of its proper divisors (1).

20439911 is an equidigital number, since it uses as much as digits as its factorization.

20439911 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 20439911 is about 4521.0519793517. The cubic root of 20439911 is about 273.4175160427.

The spelling of 20439911 in words is "twenty million, four hundred thirty-nine thousand, nine hundred eleven".