20713520 has 20 divisors (see below), whose sum is σ = 48159120. Its totient is φ = 8285376.

The previous prime is 20713489. The next prime is 20713529. The reversal of 20713520 is 2531702.

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

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 20713492 and 20713501.

It is not an unprimeable number, because it can be changed into a prime (20713529) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129380 + ... + 129539.

It is an arithmetic number, because the mean of its divisors is an integer number (2407956).

Almost surely, 2^20713520 is an apocalyptic number.

20713520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20713520 is an abundant number, since it is smaller than the sum of its proper divisors (27445600).

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

20713520 is a wasteful number, since it uses less digits than its factorization.

20713520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258932 (or 258926 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 20.

The square root of 20713520 is about 4551.2108279006. The cubic root of 20713520 is about 274.6321030857.

The spelling of 20713520 in words is "twenty million, seven hundred thirteen thousand, five hundred twenty".