20866867 has 4 divisors (see below), whose sum is σ = 23847856. Its totient is φ = 17885880.

The previous prime is 20866861. The next prime is 20866877. The reversal of 20866867 is 76866802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 76866802 = 2 ⋅38433401.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20866867 is a prime.

It is a super-2 number, since 2×20866867² = 870852276791378, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20866861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1490484 + ... + 1490497.

It is an arithmetic number, because the mean of its divisors is an integer number (5961964).

Almost surely, 2^20866867 is an apocalyptic number.

20866867 is a deficient number, since it is larger than the sum of its proper divisors (2980989).

20866867 is an equidigital number, since it uses as much as digits as its factorization.

20866867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2980988.

The product of its (nonzero) digits is 193536, while the sum is 43.

The square root of 20866867 is about 4568.0265979961. The cubic root of 20866867 is about 275.3081592374.

The spelling of 20866867 in words is "twenty million, eight hundred sixty-six thousand, eight hundred sixty-seven".