20660016 has 80 divisors (see below), whose sum is σ = 58183776. Its totient is φ = 6279168.

The previous prime is 20659999. The next prime is 20660047. The reversal of 20660016 is 61006602.

It is a super-2 number, since 2×20660016² = 853672522240512, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20659974 and 20660001.

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, 70366 + ... + 70658.

Almost surely, 2^20660016 is an apocalyptic number.

20660016 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 20660016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29091888).

20660016 is an abundant number, since it is smaller than the sum of its proper divisors (37523760).

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

20660016 is a wasteful number, since it uses less digits than its factorization.

20660016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430 (or 424 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 20660016 is about 4545.3290309943. The cubic root of 20660016 is about 274.3954366327.

Adding to 20660016 its reverse (61006602), we get a palindrome (81666618).

The spelling of 20660016 in words is "twenty million, six hundred sixty thousand, sixteen".