21232164556 has 6 divisors (see below), whose sum is σ = 37156287980. Its totient is φ = 10616082276.

The previous prime is 21232164539. The next prime is 21232164559. The reversal of 21232164556 is 65546123212.

It is not an unprimeable number, because it can be changed into a prime (21232164559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2654020566 + ... + 2654020573.

Almost surely, 2^21232164556 is an apocalyptic number.

It is an amenable number.

21232164556 is a deficient number, since it is larger than the sum of its proper divisors (15924123424).

21232164556 is a wasteful number, since it uses less digits than its factorization.

21232164556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5308041143 (or 5308041141 counting only the distinct ones).

The product of its digits is 86400, while the sum is 37.

Adding to 21232164556 its reverse (65546123212), we get a palindrome (86778287768).

The spelling of 21232164556 in words is "twenty-one billion, two hundred thirty-two million, one hundred sixty-four thousand, five hundred fifty-six".