21705074 has 8 divisors (see below), whose sum is σ = 32616540. Its totient is φ = 10832896.

The previous prime is 21705071. The next prime is 21705083. The reversal of 21705074 is 47050712.

It can be written as a sum of positive squares in 2 ways, for example, as 16345849 + 5359225 = 4043^2 + 2315^2 .

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

It is a super-2 number, since 2×21705074² = 942220474690952, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21705071) 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, 8399 + ... + 10674.

Almost surely, 2^21705074 is an apocalyptic number.

21705074 is a deficient number, since it is larger than the sum of its proper divisors (10911466).

21705074 is a wasteful number, since it uses less digits than its factorization.

21705074 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19644.

The product of its (nonzero) digits is 1960, while the sum is 26.

The square root of 21705074 is about 4658.8704639644. The cubic root of 21705074 is about 278.9461833567.

Adding to 21705074 its reverse (47050712), we get a palindrome (68755786).

The spelling of 21705074 in words is "twenty-one million, seven hundred five thousand, seventy-four".