20797440 has 96 divisors (see below), whose sum is σ = 66633840. Its totient is φ = 5537792.

The previous prime is 20797411. The next prime is 20797463. The reversal of 20797440 is 4479702.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30382 + ... + 31058.

Almost surely, 2^20797440 is an apocalyptic number.

20797440 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 20797440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33316920).

20797440 is an abundant number, since it is smaller than the sum of its proper divisors (45836400).

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

20797440 is an equidigital number, since it uses as much as digits as its factorization.

20797440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 707 (or 687 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 33.

The square root of 20797440 is about 4560.4210331942. The cubic root of 20797440 is about 275.0024903356.

The spelling of 20797440 in words is "twenty million, seven hundred ninety-seven thousand, four hundred forty".