21232430756 has 12 divisors (see below), whose sum is σ = 37161665100. Its totient is φ = 10614812160.

The previous prime is 21232430729. The next prime is 21232430761. The reversal of 21232430756 is 65703423212.

It can be written as a sum of positive squares in 2 ways, for example, as 2686348900 + 18546081856 = 51830^2 + 136184^2 .

It is a super-2 number, since 2×21232430756² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 316385 + ... + 377576.

It is an arithmetic number, because the mean of its divisors is an integer number (3096805425).

Almost surely, 2^21232430756 is an apocalyptic number.

It is an amenable number.

21232430756 is a deficient number, since it is larger than the sum of its proper divisors (15929234344).

21232430756 is a wasteful number, since it uses less digits than its factorization.

21232430756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 701614 (or 701612 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 35.

Adding to 21232430756 its reverse (65703423212), we get a palindrome (86935853968).

The spelling of 21232430756 in words is "twenty-one billion, two hundred thirty-two million, four hundred thirty thousand, seven hundred fifty-six".