21385982 has 8 divisors (see below), whose sum is σ = 33767400. Its totient is φ = 10130184.

The previous prime is 21385967. The next prime is 21385999. The reversal of 21385982 is 28958312.

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

It is a super-2 number, since 2×21385982² = 914720452208648, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (38), and also a Moran number because the ratio is a prime number: 562789 = 21385982 / (2 + 1 + 3 + 8 + 5 + 9 + 8 + 2).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 281357 + ... + 281432.

It is an arithmetic number, because the mean of its divisors is an integer number (4220925).

Almost surely, 2^21385982 is an apocalyptic number.

21385982 is a deficient number, since it is larger than the sum of its proper divisors (12381418).

21385982 is a wasteful number, since it uses less digits than its factorization.

21385982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 562810.

The product of its digits is 34560, while the sum is 38.

The square root of 21385982 is about 4624.4980268133. The cubic root of 21385982 is about 277.5724757264.

The spelling of 21385982 in words is "twenty-one million, three hundred eighty-five thousand, nine hundred eighty-two".