20816730 has 128 divisors (see below), whose sum is σ = 62346240. Its totient is φ = 4898880.

The previous prime is 20816701. The next prime is 20816759. The reversal of 20816730 is 3761802.

It is an interprime number because it is at equal distance from previous prime (20816701) and next prime (20816759).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 20816694 and 20816703.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 127629 + ... + 127791.

It is an arithmetic number, because the mean of its divisors is an integer number (487080).

Almost surely, 2^20816730 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20816730, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31173120).

20816730 is an abundant number, since it is smaller than the sum of its proper divisors (41529510).

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

20816730 is a wasteful number, since it uses less digits than its factorization.

20816730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233 (or 227 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 20816730 is about 4562.5354793141. The cubic root of 20816730 is about 275.0874873157.

The spelling of 20816730 in words is "twenty million, eight hundred sixteen thousand, seven hundred thirty".