21018342 has 8 divisors (see below), whose sum is σ = 42036696. Its totient is φ = 7006112.

The previous prime is 21018323. The next prime is 21018397. The reversal of 21018342 is 24381012.

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

21018342 is an admirable number.

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, 1751523 + ... + 1751534.

It is an arithmetic number, because the mean of its divisors is an integer number (5254587).

Almost surely, 2^21018342 is an apocalyptic number.

21018342 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.

21018342 is a wasteful number, since it uses less digits than its factorization.

21018342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3503062.

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 21018342 is about 4584.5765344250. The cubic root of 21018342 is about 275.9727183704.

Adding to 21018342 its reverse (24381012), we get a palindrome (45399354).

The spelling of 21018342 in words is "twenty-one million, eighteen thousand, three hundred forty-two".