21622205 has 16 divisors (see below), whose sum is σ = 28531008. Its totient is φ = 15600000.

The previous prime is 21622201. The next prime is 21622213. The reversal of 21622205 is 50222612.

It is not a de Polignac number, because 21622205 - 2² = 21622201 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21622201) 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, 5705 + ... + 8705.

It is an arithmetic number, because the mean of its divisors is an integer number (1783188).

Almost surely, 2^21622205 is an apocalyptic number.

It is an amenable number.

21622205 is a deficient number, since it is larger than the sum of its proper divisors (6908803).

21622205 is a wasteful number, since it uses less digits than its factorization.

21622205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3148.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 21622205 is about 4649.9682794617. The cubic root of 21622205 is about 278.5907292598.

Adding to 21622205 its reverse (50222612), we get a palindrome (71844817).

It can be divided in two parts, 21 and 622205, that added together give a palindrome (622226).

The spelling of 21622205 in words is "twenty-one million, six hundred twenty-two thousand, two hundred five".