20825891 has 2 divisors, whose sum is σ = 20825892. Its totient is φ = 20825890.

The previous prime is 20825869. The next prime is 20825921. The reversal of 20825891 is 19852802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20825891 - 2¹⁸ = 20563747 is a prime.

It is not a weakly prime, because it can be changed into another prime (20825801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10412945 + 10412946.

It is an arithmetic number, because the mean of its divisors is an integer number (10412946).

Almost surely, 2^20825891 is an apocalyptic number.

20825891 is a deficient number, since it is larger than the sum of its proper divisors (1).

20825891 is an equidigital number, since it uses as much as digits as its factorization.

20825891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 20825891 is about 4563.5393062841. The cubic root of 20825891 is about 275.1278347812.

The spelling of 20825891 in words is "twenty million, eight hundred twenty-five thousand, eight hundred ninety-one".