21743746 has 8 divisors (see below), whose sum is σ = 32642064. Its totient is φ = 10863060.

The previous prime is 21743737. The next prime is 21743749. The reversal of 21743746 is 64734712.

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

It is a super-2 number, since 2×21743746² = 945580980225032, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21743749) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 700 + ... + 6631.

It is an arithmetic number, because the mean of its divisors is an integer number (4080258).

Almost surely, 2^21743746 is an apocalyptic number.

21743746 is a deficient number, since it is larger than the sum of its proper divisors (10898318).

21743746 is a wasteful number, since it uses less digits than its factorization.

21743746 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8816.

The product of its digits is 28224, while the sum is 34.

The square root of 21743746 is about 4663.0189791593. The cubic root of 21743746 is about 279.1117515012. Note that the first 3 decimals are identical.

The spelling of 21743746 in words is "twenty-one million, seven hundred forty-three thousand, seven hundred forty-six".