20761216 has 128 divisors (see below), whose sum is σ = 52876800. Its totient is φ = 7913472.

The previous prime is 20761207. The next prime is 20761229. The reversal of 20761216 is 61216702.

20761216 = T₂₉₃ + T₂₉₄ + ... + T₅₃₀.

It is a tau number, because it is divible by the number of its divisors (128).

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, 441705 + ... + 441751.

It is an arithmetic number, because the mean of its divisors is an integer number (413100).

Almost surely, 2^20761216 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 20761216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26438400).

20761216 is an abundant number, since it is smaller than the sum of its proper divisors (32115584).

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

20761216 is a wasteful number, since it uses less digits than its factorization.

20761216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114 (or 102 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 20761216 is about 4556.4477391933. The cubic root of 20761216 is about 274.8427354264.

Adding to 20761216 its reverse (61216702), we get a palindrome (81977918).

The spelling of 20761216 in words is "twenty million, seven hundred sixty-one thousand, two hundred sixteen".