21621271331044 has 24 divisors (see below), whose sum is σ = 47173682904768. Its totient is φ = 8423871947040.

The previous prime is 21621271330993. The next prime is 21621271331083. The reversal of 21621271331044 is 44013317212612.

It is a junction number, because it is equal to n+sod(n) for n = 21621271330994 and 21621271331012.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 35099466139 + ... + 35099466754.

It is an arithmetic number, because the mean of its divisors is an integer number (1965570121032).

Almost surely, 2^{21621271331044} is an apocalyptic number.

It is an amenable number.

21621271331044 is an abundant number, since it is smaller than the sum of its proper divisors (25552411573724).

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

21621271331044 is a wasteful number, since it uses less digits than its factorization.

21621271331044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70198932915 (or 70198932913 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 37.

Adding to 21621271331044 its reverse (44013317212612), we get a palindrome (65634588543656).

The spelling of 21621271331044 in words is "twenty-one trillion, six hundred twenty-one billion, two hundred seventy-one million, three hundred thirty-one thousand, forty-four".