21261426 has 8 divisors (see below), whose sum is σ = 42522864. Its totient is φ = 7087140.

The previous prime is 21261413. The next prime is 21261433. The reversal of 21261426 is 62416212.

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

21261426 is an admirable number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21261396 and 21261405.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1771780 + ... + 1771791.

It is an arithmetic number, because the mean of its divisors is an integer number (5315358).

Almost surely, 2^21261426 is an apocalyptic number.

21261426 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.

21261426 is a wasteful number, since it uses less digits than its factorization.

21261426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3543576.

The product of its digits is 1152, while the sum is 24.

The square root of 21261426 is about 4611.0113858025. The cubic root of 21261426 is about 277.0325479703.

Adding to 21261426 its reverse (62416212), we get a palindrome (83677638).

The spelling of 21261426 in words is "twenty-one million, two hundred sixty-one thousand, four hundred twenty-six".