21621351561132 has 12 divisors (see below), whose sum is σ = 50449820309336. Its totient is φ = 7207117187040.

The previous prime is 21621351561119. The next prime is 21621351561137. The reversal of 21621351561132 is 23116515312612.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (21621351561137) 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, 900889648369 + ... + 900889648392.

Almost surely, 2^{21621351561132} is an apocalyptic number.

It is an amenable number.

21621351561132 is an abundant number, since it is smaller than the sum of its proper divisors (28828468748204).

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

21621351561132 is a wasteful number, since it uses less digits than its factorization.

21621351561132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1801779296768 (or 1801779296766 counting only the distinct ones).

The product of its digits is 64800, while the sum is 39.

Adding to 21621351561132 its reverse (23116515312612), we get a palindrome (44737866873744).

The spelling of 21621351561132 in words is "twenty-one trillion, six hundred twenty-one billion, three hundred fifty-one million, five hundred sixty-one thousand, one hundred thirty-two".