21661246556132 has 6 divisors (see below), whose sum is σ = 37907181473238. Its totient is φ = 10830623278064.

The previous prime is 21661246556129. The next prime is 21661246556149. The reversal of 21661246556132 is 23165564216612.

It can be written as a sum of positive squares in only one way, i.e., 12082617712036 + 9578628844096 = 3476006^2 + 3094936^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2707655819513 + ... + 2707655819520.

It is an arithmetic number, because the mean of its divisors is an integer number (6317863578873).

Almost surely, 2^{21661246556132} is an apocalyptic number.

It is an amenable number.

21661246556132 is a deficient number, since it is larger than the sum of its proper divisors (16245934917106).

21661246556132 is a wasteful number, since it uses less digits than its factorization.

21661246556132 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5415311639037 (or 5415311639035 counting only the distinct ones).

The product of its digits is 3110400, while the sum is 50.

The spelling of 21661246556132 in words is "twenty-one trillion, six hundred sixty-one billion, two hundred forty-six million, five hundred fifty-six thousand, one hundred thirty-two".