21661465732396 has 24 divisors (see below), whose sum is σ = 43323094321920. Its totient is φ = 9283450415952.

The previous prime is 21661465732391. The next prime is 21661465732429. The reversal of 21661465732396 is 69323756416612.

It is not an unprimeable number, because it can be changed into a prime (21661465732391) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6987135 + ... + 9599113.

It is an arithmetic number, because the mean of its divisors is an integer number (1805128930080).

Almost surely, 2^{21661465732396} is an apocalyptic number.

It is an amenable number.

21661465732396 is an abundant number, since it is smaller than the sum of its proper divisors (21661628589524).

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

21661465732396 is a wasteful number, since it uses less digits than its factorization.

21661465732396 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2908173 (or 2908171 counting only the distinct ones).

The product of its digits is 58786560, while the sum is 61.

The spelling of 21661465732396 in words is "twenty-one trillion, six hundred sixty-one billion, four hundred sixty-five million, seven hundred thirty-two thousand, three hundred ninety-six".