21207329 has 8 divisors (see below), whose sum is σ = 24915072. Its totient is φ = 17796240.

The previous prime is 21207301. The next prime is 21207331. The reversal of 21207329 is 92370212.

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

It is not a de Polignac number, because 21207329 - 2¹⁶ = 21141793 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21207298 and 21207307.

It is not an unprimeable number, because it can be changed into a prime (21207229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74009 + ... + 74294.

It is an arithmetic number, because the mean of its divisors is an integer number (3114384).

Almost surely, 2^21207329 is an apocalyptic number.

It is an amenable number.

21207329 is a deficient number, since it is larger than the sum of its proper divisors (3707743).

21207329 is a wasteful number, since it uses less digits than its factorization.

21207329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148327.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 21207329 is about 4605.1415830569. The cubic root of 21207329 is about 276.7973903618.

It can be divided in two parts, 2120 and 7329, that added together give a palindrome (9449).

The spelling of 21207329 in words is "twenty-one million, two hundred seven thousand, three hundred twenty-nine".