21431226 has 8 divisors (see below), whose sum is σ = 42862464. Its totient is φ = 7143740.

The previous prime is 21431209. The next prime is 21431231. The reversal of 21431226 is 62213412.

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

21431226 is an admirable number.

It is a Curzon number.

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, 1785930 + ... + 1785941.

It is an arithmetic number, because the mean of its divisors is an integer number (5357808).

Almost surely, 2^21431226 is an apocalyptic number.

21431226 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21431226 is a wasteful number, since it uses less digits than its factorization.

21431226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3571876.

The product of its digits is 576, while the sum is 21.

The square root of 21431226 is about 4629.3872164683. The cubic root of 21431226 is about 277.7680811667.

Adding to 21431226 its reverse (62213412), we get a palindrome (83644638).

The spelling of 21431226 in words is "twenty-one million, four hundred thirty-one thousand, two hundred twenty-six".