20516730 has 64 divisors (see below), whose sum is σ = 54770688. Its totient is φ = 4884480.

The previous prime is 20516707. The next prime is 20516737. The reversal of 20516730 is 3761502.

It is a self number, because there is not a number n which added to its sum of digits gives 20516730.

It is not an unprimeable number, because it can be changed into a prime (20516737) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11242 + ... + 12938.

It is an arithmetic number, because the mean of its divisors is an integer number (855792).

Almost surely, 2^20516730 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20516730, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27385344).

20516730 is an abundant number, since it is smaller than the sum of its proper divisors (34253958).

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

20516730 is a wasteful number, since it uses less digits than its factorization.

20516730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1751.

The product of its (nonzero) digits is 1260, while the sum is 24.

The square root of 20516730 is about 4529.5397117146. The cubic root of 20516730 is about 273.7596147662.

The spelling of 20516730 in words is "twenty million, five hundred sixteen thousand, seven hundred thirty".