20735720 has 32 divisors (see below), whose sum is σ = 47540520. Its totient is φ = 8136960.

The previous prime is 20735713. The next prime is 20735731. The reversal of 20735720 is 2753702.

It can be written as a sum of positive squares in 4 ways, for example, as 17825284 + 2910436 = 4222^2 + 1706^2 .

It is a zygodrome in base 3.

It is a self number, because there is not a number n which added to its sum of digits gives 20735720.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2771 + ... + 7010.

Almost surely, 2^20735720 is an apocalyptic number.

20735720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20735720 is an abundant number, since it is smaller than the sum of its proper divisors (26804800).

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

20735720 is a wasteful number, since it uses less digits than its factorization.

20735720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9845 (or 9841 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 26.

The square root of 20735720 is about 4553.6490861725. The cubic root of 20735720 is about 274.7301816332.

The spelling of 20735720 in words is "twenty million, seven hundred thirty-five thousand, seven hundred twenty".