21163522 has 4 divisors (see below), whose sum is σ = 31745286. Its totient is φ = 10581760.

The previous prime is 21163507. The next prime is 21163531. The reversal of 21163522 is 22536112.

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., 20602521 + 561001 = 4539^2 + 749^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21163493 and 21163502.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5290879 + ... + 5290882.

Almost surely, 2^21163522 is an apocalyptic number.

21163522 is a deficient number, since it is larger than the sum of its proper divisors (10581764).

21163522 is a wasteful number, since it uses less digits than its factorization.

21163522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10581763.

The product of its digits is 720, while the sum is 22.

The square root of 21163522 is about 4600.3828101583. The cubic root of 21163522 is about 276.6066697857.

Adding to 21163522 its reverse (22536112), we get a palindrome (43699634).

The spelling of 21163522 in words is "twenty-one million, one hundred sixty-three thousand, five hundred twenty-two".