20858516 has 48 divisors (see below), whose sum is σ = 44486400. Its totient is φ = 8537760.

The previous prime is 20858503. The next prime is 20858527. The reversal of 20858516 is 61585802.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31226 + ... + 31886.

It is an arithmetic number, because the mean of its divisors is an integer number (926800).

Almost surely, 2^20858516 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20858516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22243200).

20858516 is an abundant number, since it is smaller than the sum of its proper divisors (23627884).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20858516 is a wasteful number, since it uses less digits than its factorization.

20858516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 709 (or 693 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 35.

The square root of 20858516 is about 4567.1124356644. The cubic root of 20858516 is about 275.2714278775.

It can be divided in two parts, 2085 and 8516, that added together give a palindrome (10601).

The spelling of 20858516 in words is "twenty million, eight hundred fifty-eight thousand, five hundred sixteen".