21206234 has 8 divisors (see below), whose sum is σ = 36353568. Its totient is φ = 9088380.

The previous prime is 21206233. The next prime is 21206239. The reversal of 21206234 is 43260212.

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

It is not an unprimeable number, because it can be changed into a prime (21206233) 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, 757352 + ... + 757379.

It is an arithmetic number, because the mean of its divisors is an integer number (4544196).

Almost surely, 2^21206234 is an apocalyptic number.

21206234 is a deficient number, since it is larger than the sum of its proper divisors (15147334).

21206234 is a wasteful number, since it uses less digits than its factorization.

21206234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1514740.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 21206234 is about 4605.0226926694. The cubic root of 21206234 is about 276.7926263113.

Adding to 21206234 its reverse (43260212), we get a palindrome (64466446).

The spelling of 21206234 in words is "twenty-one million, two hundred six thousand, two hundred thirty-four".