21705674 has 8 divisors (see below), whose sum is σ = 33004740. Its totient is φ = 10704096.

The previous prime is 21705667. The next prime is 21705679. The reversal of 21705674 is 47650712.

It can be written as a sum of positive squares in 2 ways, for example, as 21557449 + 148225 = 4643^2 + 385^2 .

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

It is a super-2 number, since 2×21705674² = 942272567588552, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21705674.

It is not an unprimeable number, because it can be changed into a prime (21705679) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 74189 + ... + 74480.

Almost surely, 2^21705674 is an apocalyptic number.

21705674 is a deficient number, since it is larger than the sum of its proper divisors (11299066).

21705674 is a wasteful number, since it uses less digits than its factorization.

21705674 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148744.

The product of its (nonzero) digits is 11760, while the sum is 32.

The square root of 21705674 is about 4658.9348568101. The cubic root of 21705674 is about 278.9487536646.

The spelling of 21705674 in words is "twenty-one million, seven hundred five thousand, six hundred seventy-four".