20858887 has 4 divisors (see below), whose sum is σ = 23838736. Its totient is φ = 17879040.

The previous prime is 20858879. The next prime is 20858897. The reversal of 20858887 is 78885802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78885802 = 2 ⋅39442901.

It is a cyclic number.

It is not a de Polignac number, because 20858887 - 2³ = 20858879 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20858807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1489914 + ... + 1489927.

It is an arithmetic number, because the mean of its divisors is an integer number (5959684).

Almost surely, 2^20858887 is an apocalyptic number.

20858887 is a deficient number, since it is larger than the sum of its proper divisors (2979849).

20858887 is an equidigital number, since it uses as much as digits as its factorization.

20858887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2979848.

The product of its (nonzero) digits is 286720, while the sum is 46.

The square root of 20858887 is about 4567.1530519570. The cubic root of 20858887 is about 275.2730599062.

It can be divided in two parts, 208 and 58887, that added together give a palindrome (59095).

The spelling of 20858887 in words is "twenty million, eight hundred fifty-eight thousand, eight hundred eighty-seven".