21207332 has 12 divisors (see below), whose sum is σ = 38018316. Its totient is φ = 10344960.

The previous prime is 21207331. The next prime is 21207341. The reversal of 21207332 is 23370212.

It can be written as a sum of positive squares in 2 ways, for example, as 6584356 + 14622976 = 2566^2 + 3824^2 .

It is not an unprimeable number, because it can be changed into a prime (21207331) 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, 64493 + ... + 64820.

It is an arithmetic number, because the mean of its divisors is an integer number (3168193).

Almost surely, 2^21207332 is an apocalyptic number.

It is an amenable number.

21207332 is a deficient number, since it is larger than the sum of its proper divisors (16810984).

21207332 is a wasteful number, since it uses less digits than its factorization.

21207332 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129358 (or 129356 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 20.

The square root of 21207332 is about 4605.1419087798. The cubic root of 21207332 is about 276.7974034138.

Adding to 21207332 its reverse (23370212), we get a palindrome (44577544).

The spelling of 21207332 in words is "twenty-one million, two hundred seven thousand, three hundred thirty-two".