20716720 has 20 divisors (see below), whose sum is σ = 48166560. Its totient is φ = 8286656.

The previous prime is 20716697. The next prime is 20716739. The reversal of 20716720 is 2761702.

It is a tau number, because it is divible by the number of its divisors (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129400 + ... + 129559.

It is an arithmetic number, because the mean of its divisors is an integer number (2408328).

Almost surely, 2^20716720 is an apocalyptic number.

20716720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20716720 is an abundant number, since it is smaller than the sum of its proper divisors (27449840).

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

20716720 is a wasteful number, since it uses less digits than its factorization.

20716720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258972 (or 258966 counting only the distinct ones).

The product of its (nonzero) digits is 1176, while the sum is 25.

The square root of 20716720 is about 4551.5623691212. The cubic root of 20716720 is about 274.6462448553.

The spelling of 20716720 in words is "twenty million, seven hundred sixteen thousand, seven hundred twenty".