21400323 has 32 divisors (see below), whose sum is σ = 34209792. Its totient is φ = 11642400.

The previous prime is 21400277. The next prime is 21400343. The reversal of 21400323 is 32300412.

It is not a de Polignac number, because 21400323 - 2¹⁰ = 21399299 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21400343) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 45990 + ... + 46452.

It is an arithmetic number, because the mean of its divisors is an integer number (1069056).

Almost surely, 2^21400323 is an apocalyptic number.

21400323 is a deficient number, since it is larger than the sum of its proper divisors (12809469).

21400323 is a wasteful number, since it uses less digits than its factorization.

21400323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 575.

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 21400323 is about 4626.0483136258. The cubic root of 21400323 is about 277.6345066621.

Adding to 21400323 its reverse (32300412), we get a palindrome (53700735).

The spelling of 21400323 in words is "twenty-one million, four hundred thousand, three hundred twenty-three".