20787920 has 40 divisors (see below), whose sum is σ = 49464096. Its totient is φ = 8120448.

The previous prime is 20787917. The next prime is 20787941. The reversal of 20787920 is 2978702.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-3 number, since 3×20787920³ (a number of 23 digits) contains 333 as substring.

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, 419 + ... + 6461.

Almost surely, 2^20787920 is an apocalyptic number.

20787920 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 20787920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24732048).

20787920 is an abundant number, since it is smaller than the sum of its proper divisors (28676176).

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

20787920 is a wasteful number, since it uses less digits than its factorization.

20787920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6099 (or 6093 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 35.

The square root of 20787920 is about 4559.3771504450. The cubic root of 20787920 is about 274.9605232589.

The spelling of 20787920 in words is "twenty million, seven hundred eighty-seven thousand, nine hundred twenty".