21431426 has 8 divisors (see below), whose sum is σ = 32224764. Its totient is φ = 10689840.

The previous prime is 21431401. The next prime is 21431489. The reversal of 21431426 is 62413412.

It can be written as a sum of positive squares in 2 ways, for example, as 18705625 + 2725801 = 4325^2 + 1651^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11885 + ... + 13568.

Almost surely, 2^21431426 is an apocalyptic number.

21431426 is a deficient number, since it is larger than the sum of its proper divisors (10793338).

21431426 is a wasteful number, since it uses less digits than its factorization.

21431426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25876.

The product of its digits is 1152, while the sum is 23.

The square root of 21431426 is about 4629.4088175490. The cubic root of 21431426 is about 277.7689452243.

Adding to 21431426 its reverse (62413412), we get a palindrome (83844838).

The spelling of 21431426 in words is "twenty-one million, four hundred thirty-one thousand, four hundred twenty-six".