21371744 has 12 divisors (see below), whose sum is σ = 42075684. Its totient is φ = 10685856.

The previous prime is 21371717. The next prime is 21371759. The reversal of 21371744 is 44717312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333902 + ... + 333965.

It is an arithmetic number, because the mean of its divisors is an integer number (3506307).

Almost surely, 2^21371744 is an apocalyptic number.

It is an amenable number.

21371744 is a deficient number, since it is larger than the sum of its proper divisors (20703940).

21371744 is an equidigital number, since it uses as much as digits as its factorization.

21371744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 667877 (or 667869 counting only the distinct ones).

The product of its digits is 4704, while the sum is 29.

The square root of 21371744 is about 4622.9583601845. The cubic root of 21371744 is about 277.5108628705.

The spelling of 21371744 in words is "twenty-one million, three hundred seventy-one thousand, seven hundred forty-four".