21422505 has 16 divisors (see below), whose sum is σ = 36912960. Its totient is φ = 10546368.

The previous prime is 21422501. The next prime is 21422537. The reversal of 21422505 is 50522412.

It is a happy number.

It is not a de Polignac number, because 21422505 - 2² = 21422501 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21422501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54735 + ... + 55124.

It is an arithmetic number, because the mean of its divisors is an integer number (2307060).

Almost surely, 2^21422505 is an apocalyptic number.

It is an amenable number.

21422505 is a deficient number, since it is larger than the sum of its proper divisors (15490455).

21422505 is a wasteful number, since it uses less digits than its factorization.

21422505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109880.

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 21422505 is about 4628.4452033053. The cubic root of 21422505 is about 277.7303987044.

Adding to 21422505 its reverse (50522412), we get a palindrome (71944917).

The spelling of 21422505 in words is "twenty-one million, four hundred twenty-two thousand, five hundred five".