21740416 has 64 divisors (see below), whose sum is σ = 46781280. Its totient is φ = 10027008.

The previous prime is 21740387. The next prime is 21740417. The reversal of 21740416 is 61404712.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21740417) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 211021 + ... + 211123.

Almost surely, 2^21740416 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21740416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23390640).

21740416 is an abundant number, since it is smaller than the sum of its proper divisors (25040864).

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

21740416 is a wasteful number, since it uses less digits than its factorization.

21740416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231 (or 219 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 21740416 is about 4662.6619006743. The cubic root of 21740416 is about 279.0975023529.

The spelling of 21740416 in words is "twenty-one million, seven hundred forty thousand, four hundred sixteen".