21385758 has 8 divisors (see below), whose sum is σ = 42771528. Its totient is φ = 7128584.

The previous prime is 21385757. The next prime is 21385781. The reversal of 21385758 is 85758312.

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

21385758 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21385757) by changing a digit.

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, 1782141 + ... + 1782152.

It is an arithmetic number, because the mean of its divisors is an integer number (5346441).

Almost surely, 2^21385758 is an apocalyptic number.

21385758 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.

21385758 is a wasteful number, since it uses less digits than its factorization.

21385758 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3564298.

The product of its digits is 67200, while the sum is 39.

The square root of 21385758 is about 4624.4738079051. The cubic root of 21385758 is about 277.5715066110.

The spelling of 21385758 in words is "twenty-one million, three hundred eighty-five thousand, seven hundred fifty-eight".