21621122 has 4 divisors (see below), whose sum is σ = 32431686. Its totient is φ = 10810560.

The previous prime is 21621121. The next prime is 21621137. The reversal of 21621122 is 22112612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 21613201 + 7921 = 4649^2 + 89^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21621122.

It is not an unprimeable number, because it can be changed into a prime (21621121) by changing a digit.

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 as a sum of consecutive naturals, namely, 5405279 + ... + 5405282.

Almost surely, 2^21621122 is an apocalyptic number.

21621122 is a deficient number, since it is larger than the sum of its proper divisors (10810564).

21621122 is a wasteful number, since it uses less digits than its factorization.

21621122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10810563.

The product of its digits is 96, while the sum is 17.

The square root of 21621122 is about 4649.8518255962. The cubic root of 21621122 is about 278.5860778871.

Adding to 21621122 its reverse (22112612), we get a palindrome (43733734).

The spelling of 21621122 in words is "twenty-one million, six hundred twenty-one thousand, one hundred twenty-two".