20764560 has 80 divisors (see below), whose sum is σ = 64817280. Its totient is φ = 5498880.

The previous prime is 20764547. The next prime is 20764567. The reversal of 20764560 is 6546702.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20764567) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 57661 + ... + 58019.

It is an arithmetic number, because the mean of its divisors is an integer number (810216).

Almost surely, 2^20764560 is an apocalyptic number.

20764560 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 20764560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32408640).

20764560 is an abundant number, since it is smaller than the sum of its proper divisors (44052720).

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

20764560 is a wasteful number, since it uses less digits than its factorization.

20764560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616 (or 610 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 30.

The square root of 20764560 is about 4556.8146769427. The cubic root of 20764560 is about 274.8574909007.

The spelling of 20764560 in words is "twenty million, seven hundred sixty-four thousand, five hundred sixty".