20865887 has 8 divisors (see below), whose sum is σ = 23955456. Its totient is φ = 17803512.

The previous prime is 20865863. The next prime is 20865931. The reversal of 20865887 is 78856802.

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

It is a cyclic number.

It is not a de Polignac number, because 20865887 - 2¹⁰ = 20864863 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20865827) 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, 5123 + ... + 8244.

It is an arithmetic number, because the mean of its divisors is an integer number (2994432).

Almost surely, 2^20865887 is an apocalyptic number.

20865887 is a deficient number, since it is larger than the sum of its proper divisors (3089569).

20865887 is a wasteful number, since it uses less digits than its factorization.

20865887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13597.

The product of its (nonzero) digits is 215040, while the sum is 44.

The square root of 20865887 is about 4567.9193294103. The cubic root of 20865887 is about 275.3038492753.

The spelling of 20865887 in words is "twenty million, eight hundred sixty-five thousand, eight hundred eighty-seven".