20797520 has 80 divisors (see below), whose sum is σ = 51425280. Its totient is φ = 7805952.

The previous prime is 20797507. The next prime is 20797531. The reversal of 20797520 is 2579702.

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

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 163697 + ... + 163823.

It is an arithmetic number, because the mean of its divisors is an integer number (642816).

Almost surely, 2^20797520 is an apocalyptic number.

20797520 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 20797520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25712640).

20797520 is an abundant number, since it is smaller than the sum of its proper divisors (30627760).

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

20797520 is a wasteful number, since it uses less digits than its factorization.

20797520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252 (or 246 counting only the distinct ones).

The product of its (nonzero) digits is 8820, while the sum is 32.

The square root of 20797520 is about 4560.4298043057. The cubic root of 20797520 is about 275.0028429458.

The spelling of 20797520 in words is "twenty million, seven hundred ninety-seven thousand, five hundred twenty".