20707720 has 64 divisors (see below), whose sum is σ = 53524800. Its totient is φ = 7130880.

The previous prime is 20707699. The next prime is 20707723. The reversal of 20707720 is 2770702.

It is not an unprimeable number, because it can be changed into a prime (20707723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7122 + ... + 9598.

It is an arithmetic number, because the mean of its divisors is an integer number (836325).

Almost surely, 2^20707720 is an apocalyptic number.

20707720 is a gapful number since it is divisible by the number (20) 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 20707720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26762400).

20707720 is an abundant number, since it is smaller than the sum of its proper divisors (32817080).

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

20707720 is a wasteful number, since it uses less digits than its factorization.

20707720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2518 (or 2514 counting only the distinct ones).

The product of its (nonzero) digits is 1372, while the sum is 25.

The square root of 20707720 is about 4550.5735902191. The cubic root of 20707720 is about 274.6064674157.

The spelling of 20707720 in words is "twenty million, seven hundred seven thousand, seven hundred twenty".