21426461 has 4 divisors (see below), whose sum is σ = 24487392. Its totient is φ = 18365532.

The previous prime is 21426439. The next prime is 21426463. The reversal of 21426461 is 16462412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21426461 - 2²² = 17232157 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21426461.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21426463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1530455 + ... + 1530468.

It is an arithmetic number, because the mean of its divisors is an integer number (6121848).

Almost surely, 2^21426461 is an apocalyptic number.

It is an amenable number.

21426461 is a deficient number, since it is larger than the sum of its proper divisors (3060931).

21426461 is an equidigital number, since it uses as much as digits as its factorization.

21426461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3060930.

The product of its digits is 2304, while the sum is 26.

The square root of 21426461 is about 4628.8725409110. The cubic root of 21426461 is about 277.7474934036.

Adding to 21426461 its reverse (16462412), we get a palindrome (37888873).

The spelling of 21426461 in words is "twenty-one million, four hundred twenty-six thousand, four hundred sixty-one".