21075738 has 8 divisors (see below), whose sum is σ = 42151488. Its totient is φ = 7025244.

The previous prime is 21075727. The next prime is 21075749. The reversal of 21075738 is 83757012.

It is an interprime number because it is at equal distance from previous prime (21075727) and next prime (21075749).

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

21075738 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21075699 and 21075708.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1756306 + ... + 1756317.

It is an arithmetic number, because the mean of its divisors is an integer number (5268936).

Almost surely, 2^21075738 is an apocalyptic number.

21075738 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21075738 is a wasteful number, since it uses less digits than its factorization.

21075738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3512628.

The product of its (nonzero) digits is 11760, while the sum is 33.

The square root of 21075738 is about 4590.8319507471. The cubic root of 21075738 is about 276.2236949353.

The spelling of 21075738 in words is "twenty-one million, seventy-five thousand, seven hundred thirty-eight".