20581019 has 2 divisors, whose sum is σ = 20581020. Its totient is φ = 20581018.

The previous prime is 20581003. The next prime is 20581027. The reversal of 20581019 is 91018502.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20581019 - 2⁴ = 20581003 is a prime.

It is a super-2 number, since 2×20581019² = 847156686156722, which contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (20581049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10290509 + 10290510.

It is an arithmetic number, because the mean of its divisors is an integer number (10290510).

Almost surely, 2^20581019 is an apocalyptic number.

20581019 is a deficient number, since it is larger than the sum of its proper divisors (1).

20581019 is an equidigital number, since it uses as much as digits as its factorization.

20581019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 26.

The square root of 20581019 is about 4536.6307982907. The cubic root of 20581019 is about 274.0452577665.

The spelling of 20581019 in words is "twenty million, five hundred eighty-one thousand, nineteen".