20015216 has 40 divisors (see below), whose sum is σ = 42799344. Its totient is φ = 9008640.

The previous prime is 20015207. The next prime is 20015231. The reversal of 20015216 is 61251002.

It is a junction number, because it is equal to n+sod(n) for n = 20015194 and 20015203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7355 + ... + 9701.

Almost surely, 2^20015216 is an apocalyptic number.

20015216 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20015216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21399672).

20015216 is an abundant number, since it is smaller than the sum of its proper divisors (22784128).

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

20015216 is a wasteful number, since it uses less digits than its factorization.

20015216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2409 (or 2403 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 20015216 is about 4473.8368320715. The cubic root of 20015216 is about 271.5105818404.

Adding to 20015216 its reverse (61251002), we get a palindrome (81266218).

The spelling of 20015216 in words is "twenty million, fifteen thousand, two hundred sixteen".