21019938 has 8 divisors (see below), whose sum is σ = 42039888. Its totient is φ = 7006644.

The previous prime is 21019937. The next prime is 21019961. The reversal of 21019938 is 83991012.

21019938 is nontrivially palindromic in base 13.

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

21019938 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21019899 and 21019908.

It is not an unprimeable number, because it can be changed into a prime (21019937) 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, 1751656 + ... + 1751667.

It is an arithmetic number, because the mean of its divisors is an integer number (5254986).

Almost surely, 2^21019938 is an apocalyptic number.

21019938 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.

21019938 is a wasteful number, since it uses less digits than its factorization.

21019938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3503328.

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 21019938 is about 4584.7505929985. The cubic root of 21019938 is about 275.9797034014.

The spelling of 21019938 in words is "twenty-one million, nineteen thousand, nine hundred thirty-eight".