21671834 has 4 divisors (see below), whose sum is σ = 32507754. Its totient is φ = 10835916.

The previous prime is 21671831. The next prime is 21671851. The reversal of 21671834 is 43817612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 21669025 + 2809 = 4655^2 + 53^2 .

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 21671834.

It is not an unprimeable number, because it can be changed into a prime (21671831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5417957 + ... + 5417960.

Almost surely, 2^21671834 is an apocalyptic number.

21671834 is a deficient number, since it is larger than the sum of its proper divisors (10835920).

21671834 is a wasteful number, since it uses less digits than its factorization.

21671834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10835919.

The product of its digits is 8064, while the sum is 32.

The square root of 21671834 is about 4655.3017088047. The cubic root of 21671834 is about 278.8037142360.

The spelling of 21671834 in words is "twenty-one million, six hundred seventy-one thousand, eight hundred thirty-four".