21743694 has 128 divisors (see below), whose sum is σ = 59996160. Its totient is φ = 5702400.

The previous prime is 21743693. The next prime is 21743699. The reversal of 21743694 is 49634712.

21743694 is a `hidden beast` number, since 217 + 436 + 9 + 4 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21743693) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 356424 + ... + 356484.

It is an arithmetic number, because the mean of its divisors is an integer number (468720).

Almost surely, 2^21743694 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21743694, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29998080).

21743694 is an abundant number, since it is smaller than the sum of its proper divisors (38252466).

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

21743694 is a wasteful number, since it uses less digits than its factorization.

21743694 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143 (or 137 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 21743694 is about 4663.0134033691. The cubic root of 21743694 is about 279.1115290032. Note that the first 3 decimals are identical.

The spelling of 21743694 in words is "twenty-one million, seven hundred forty-three thousand, six hundred ninety-four".