21059418 has 8 divisors (see below), whose sum is σ = 42118848. Its totient is φ = 7019804.

The previous prime is 21059417. The next prime is 21059449. The reversal of 21059418 is 81495012.

It is a happy number.

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

21059418 is an admirable number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21059411) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1754946 + ... + 1754957.

It is an arithmetic number, because the mean of its divisors is an integer number (5264856).

Almost surely, 2^21059418 is an apocalyptic number.

21059418 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.

21059418 is a wasteful number, since it uses less digits than its factorization.

21059418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3509908.

The product of its (nonzero) digits is 2880, while the sum is 30.

The square root of 21059418 is about 4589.0541509117. The cubic root of 21059418 is about 276.1523785748.

The spelling of 21059418 in words is "twenty-one million, fifty-nine thousand, four hundred eighteen".