21324051 has 12 divisors (see below), whose sum is σ = 35201712. Its totient is φ = 12185136.

The previous prime is 21324047. The next prime is 21324053. The reversal of 21324051 is 15042312.

It is not a de Polignac number, because 21324051 - 2² = 21324047 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21324053) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 169176 + ... + 169301.

It is an arithmetic number, because the mean of its divisors is an integer number (2933476).

Almost surely, 2^21324051 is an apocalyptic number.

21324051 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21324051 is a deficient number, since it is larger than the sum of its proper divisors (13877661).

21324051 is a wasteful number, since it uses less digits than its factorization.

21324051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338490 (or 338487 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21324051 is about 4617.7972021300. The cubic root of 21324051 is about 277.3042788393.

Adding to 21324051 its reverse (15042312), we get a palindrome (36366363).

The spelling of 21324051 in words is "twenty-one million, three hundred twenty-four thousand, fifty-one".