21232430661 has 32 divisors (see below), whose sum is σ = 30644490240. Its totient is φ = 12999020544.

The previous prime is 21232430641. The next prime is 21232430671. The reversal of 21232430661 is 16603423212.

It is not a de Polignac number, because 21232430661 - 2¹⁴ = 21232414277 is a prime.

It is a super-2 number, since 2×21232430661² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21232430641) 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 in 31 ways as a sum of consecutive naturals, for example, 12766716 + ... + 12768378.

It is an arithmetic number, because the mean of its divisors is an integer number (957640320).

Almost surely, 2^21232430661 is an apocalyptic number.

It is an amenable number.

21232430661 is a deficient number, since it is larger than the sum of its proper divisors (9412059579).

21232430661 is a wasteful number, since it uses less digits than its factorization.

21232430661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3165.

The product of its (nonzero) digits is 10368, while the sum is 30.

Adding to 21232430661 its reverse (16603423212), we get a palindrome (37835853873).

The spelling of 21232430661 in words is "twenty-one billion, two hundred thirty-two million, four hundred thirty thousand, six hundred sixty-one".