21137938 has 8 divisors (see below), whose sum is σ = 31785660. Its totient is φ = 10542720.

The previous prime is 21137929. The next prime is 21137959. The reversal of 21137938 is 83973112.

It can be written as a sum of positive squares in 2 ways, for example, as 20820969 + 316969 = 4563^2 + 563^2 .

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

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, 12103 + ... + 13738.

Almost surely, 2^21137938 is an apocalyptic number.

21137938 is a deficient number, since it is larger than the sum of its proper divisors (10647722).

21137938 is a wasteful number, since it uses less digits than its factorization.

21137938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26252.

The product of its digits is 9072, while the sum is 34.

The square root of 21137938 is about 4597.6013311291. The cubic root of 21137938 is about 276.4951641083.

The spelling of 21137938 in words is "twenty-one million, one hundred thirty-seven thousand, nine hundred thirty-eight".