21393522 has 12 divisors (see below), whose sum is σ = 46352670. Its totient is φ = 7131168.

The previous prime is 21393521. The next prime is 21393551. The reversal of 21393522 is 22539312.

21393522 is a `hidden beast` number, since 2 + 139 + 3 + 522 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16818201 + 4575321 = 4101^2 + 2139^2 .

It is not an unprimeable number, because it can be changed into a prime (21393521) 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 5 ways as a sum of consecutive naturals, for example, 594247 + ... + 594282.

Almost surely, 2^21393522 is an apocalyptic number.

21393522 is an abundant number, since it is smaller than the sum of its proper divisors (24959148).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21393522 is a wasteful number, since it uses less digits than its factorization.

21393522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1188537 (or 1188534 counting only the distinct ones).

The product of its digits is 3240, while the sum is 27.

The square root of 21393522 is about 4625.3131785859. The cubic root of 21393522 is about 277.6050928952.

The spelling of 21393522 in words is "twenty-one million, three hundred ninety-three thousand, five hundred twenty-two".