21561311032 has 16 divisors (see below), whose sum is σ = 41520092760. Its totient is φ = 10489286304.

The previous prime is 21561310997. The next prime is 21561311039. The reversal of 21561311032 is 23011316512.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21561310988 and 21561311006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21561311039) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36420838 + ... + 36421429.

Almost surely, 2^21561311032 is an apocalyptic number.

It is an amenable number.

21561311032 is a deficient number, since it is larger than the sum of its proper divisors (19958781728).

21561311032 is a wasteful number, since it uses less digits than its factorization.

21561311032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72842310 (or 72842306 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 25.

Adding to 21561311032 its reverse (23011316512), we get a palindrome (44572627544).

The spelling of 21561311032 in words is "twenty-one billion, five hundred sixty-one million, three hundred eleven thousand, thirty-two".