21913743 has 8 divisors (see below), whose sum is σ = 29570688. Its totient is φ = 14432984.

The previous prime is 21913741. The next prime is 21913769. The reversal of 21913743 is 34731912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21913743 - 2¹ = 21913741 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21913743.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21913741) 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, 43755 + ... + 44252.

It is an arithmetic number, because the mean of its divisors is an integer number (3696336).

Almost surely, 2^21913743 is an apocalyptic number.

21913743 is a deficient number, since it is larger than the sum of its proper divisors (7656945).

21913743 is an equidigital number, since it uses as much as digits as its factorization.

21913743 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88093.

The product of its digits is 4536, while the sum is 30.

The square root of 21913743 is about 4681.2117021130. The cubic root of 21913743 is about 279.8372481048.

The spelling of 21913743 in words is "twenty-one million, nine hundred thirteen thousand, seven hundred forty-three".