20780216 has 16 divisors (see below), whose sum is σ = 39094440. Its totient is φ = 10355040.

The previous prime is 20780197. The next prime is 20780219. The reversal of 20780216 is 61208702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20780219) 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, 1775 + ... + 6686.

Almost surely, 2^20780216 is an apocalyptic number.

It is an amenable number.

20780216 is a deficient number, since it is larger than the sum of its proper divisors (18314224).

20780216 is a wasteful number, since it uses less digits than its factorization.

20780216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8774 (or 8770 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 20780216 is about 4558.5322199147. The cubic root of 20780216 is about 274.9265522860.

Adding to 20780216 its reverse (61208702), we get a palindrome (81988918).

The spelling of 20780216 in words is "twenty million, seven hundred eighty thousand, two hundred sixteen".