21385574 has 8 divisors (see below), whose sum is σ = 36661008. Its totient is φ = 9165240.

The previous prime is 21385549. The next prime is 21385591. The reversal of 21385574 is 47558312.

It is a happy number.

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

It is a congruent number.

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, 763757 + ... + 763784.

It is an arithmetic number, because the mean of its divisors is an integer number (4582626).

Almost surely, 2^21385574 is an apocalyptic number.

21385574 is a deficient number, since it is larger than the sum of its proper divisors (15275434).

21385574 is a wasteful number, since it uses less digits than its factorization.

21385574 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1527550.

The product of its digits is 33600, while the sum is 35.

The square root of 21385574 is about 4624.4539137070. The cubic root of 21385574 is about 277.5707105469.

The spelling of 21385574 in words is "twenty-one million, three hundred eighty-five thousand, five hundred seventy-four".