21767040 has 96 divisors (see below), whose sum is σ = 75184200. Its totient is φ = 5803008.

The previous prime is 21767029. The next prime is 21767059. The reversal of 21767040 is 4076712.

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

It is a junction number, because it is equal to n+sod(n) for n = 21766995 and 21767013.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3871 + ... + 7649.

Almost surely, 2^21767040 is an apocalyptic number.

21767040 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 21767040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37592100).

21767040 is an abundant number, since it is smaller than the sum of its proper divisors (53417160).

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

21767040 is a wasteful number, since it uses less digits than its factorization.

21767040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3804 (or 3789 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 21767040 is about 4665.5160486274. The cubic root of 21767040 is about 279.2113864153.

It can be divided in two parts, 2176 and 7040, that added together give a square (9216 = 96²).

The spelling of 21767040 in words is "twenty-one million, seven hundred sixty-seven thousand, forty".