21331426 has 8 divisors (see below), whose sum is σ = 32093100. Its totient is φ = 10633728.

The previous prime is 21331399. The next prime is 21331451. The reversal of 21331426 is 62413312.

It can be written as a sum of positive squares in 2 ways, for example, as 21150801 + 180625 = 4599^2 + 425^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 21331397 and 21331406.

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, 15151 + ... + 16498.

Almost surely, 2^21331426 is an apocalyptic number.

21331426 is a deficient number, since it is larger than the sum of its proper divisors (10761674).

21331426 is a wasteful number, since it uses less digits than its factorization.

21331426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31988.

The product of its digits is 864, while the sum is 22.

The square root of 21331426 is about 4618.5956740117. The cubic root of 21331426 is about 277.3362440497.

Adding to 21331426 its reverse (62413312), we get a palindrome (83744738).

The spelling of 21331426 in words is "twenty-one million, three hundred thirty-one thousand, four hundred twenty-six".