21531122 has 8 divisors (see below), whose sum is σ = 32328156. Its totient is φ = 10755072.

The previous prime is 21531121. The next prime is 21531127. The reversal of 21531122 is 22113512.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 17732521 + 3798601 = 4211^2 + 1949^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 21531122.

It is not an unprimeable number, because it can be changed into a prime (21531121) 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 in 3 ways as a sum of consecutive naturals, for example, 2363 + ... + 6974.

Almost surely, 2^21531122 is an apocalyptic number.

21531122 is a deficient number, since it is larger than the sum of its proper divisors (10797034).

21531122 is a wasteful number, since it uses less digits than its factorization.

21531122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10492.

The product of its digits is 120, while the sum is 17.

The square root of 21531122 is about 4640.1640057222. The cubic root of 21531122 is about 278.1989931816.

Adding to 21531122 its reverse (22113512), we get a palindrome (43644634).

The spelling of 21531122 in words is "twenty-one million, five hundred thirty-one thousand, one hundred twenty-two".