21404734 has 32 divisors (see below), whose sum is σ = 37134720. Its totient is φ = 9165312.

The previous prime is 21404731. The next prime is 21404741. The reversal of 21404734 is 43740412.

It is a super-2 number, since 2×21404734² = 916325275221512, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21404699 and 21404708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21404731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34612 + ... + 35224.

It is an arithmetic number, because the mean of its divisors is an integer number (1160460).

Almost surely, 2^21404734 is an apocalyptic number.

21404734 is a deficient number, since it is larger than the sum of its proper divisors (15729986).

21404734 is a wasteful number, since it uses less digits than its factorization.

21404734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 724.

The product of its (nonzero) digits is 2688, while the sum is 25.

The square root of 21404734 is about 4626.5250458633. The cubic root of 21404734 is about 277.6535805436.

The spelling of 21404734 in words is "twenty-one million, four hundred four thousand, seven hundred thirty-four".