20505867 has 8 divisors (see below), whose sum is σ = 27648720. Its totient is φ = 13516800.

The previous prime is 20505853. The next prime is 20505869. The reversal of 20505867 is 76850502.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20505867 - 2⁴ = 20505851 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20505869) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38134 + ... + 38667.

It is an arithmetic number, because the mean of its divisors is an integer number (3456090).

Almost surely, 2^20505867 is an apocalyptic number.

20505867 is a deficient number, since it is larger than the sum of its proper divisors (7142853).

20505867 is an equidigital number, since it uses as much as digits as its factorization.

20505867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76893.

The product of its (nonzero) digits is 16800, while the sum is 33.

The square root of 20505867 is about 4528.3404244822. The cubic root of 20505867 is about 273.7112903711.

The spelling of 20505867 in words is "twenty million, five hundred five thousand, eight hundred sixty-seven".