21769440 has 384 divisors, whose sum is σ = 92897280. Its totient is φ = 4147200.

The previous prime is 21769417. The next prime is 21769453. The reversal of 21769440 is 4496712.

It is a happy number.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 702225 + ... + 702255.

It is an arithmetic number, because the mean of its divisors is an integer number (241920).

Almost surely, 2^21769440 is an apocalyptic number.

21769440 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 21769440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46448640).

21769440 is an abundant number, since it is smaller than the sum of its proper divisors (71127840).

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

21769440 is a wasteful number, since it uses less digits than its factorization.

21769440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 21769440 is about 4665.7732478122. The cubic root of 21769440 is about 279.2216478427.

The spelling of 21769440 in words is "twenty-one million, seven hundred sixty-nine thousand, four hundred forty".