21431450 has 12 divisors (see below), whose sum is σ = 39862590. Its totient is φ = 8572560.

The previous prime is 21431401. The next prime is 21431489. The reversal of 21431450 is 5413412.

It can be written as a sum of positive squares in 3 ways, for example, as 9369721 + 12061729 = 3061^2 + 3473^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 214265 + ... + 214364.

Almost surely, 2^21431450 is an apocalyptic number.

21431450 is a deficient number, since it is larger than the sum of its proper divisors (18431140).

21431450 is a wasteful number, since it uses less digits than its factorization.

21431450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428641 (or 428636 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 21431450 is about 4629.4114096719. The cubic root of 21431450 is about 277.7690489109.

Adding to 21431450 its reverse (5413412), we get a palindrome (26844862).

The spelling of 21431450 in words is "twenty-one million, four hundred thirty-one thousand, four hundred fifty".