21531405333212 has 12 divisors (see below), whose sum is σ = 37683980309976. Its totient is φ = 10764553816080.

The previous prime is 21531405333203. The next prime is 21531405333223. The reversal of 21531405333212 is 21233350413512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 287170463 + ... + 287245430.

It is an arithmetic number, because the mean of its divisors is an integer number (3140331692498).

Almost surely, 2^{21531405333212} is an apocalyptic number.

It is an amenable number.

21531405333212 is a deficient number, since it is larger than the sum of its proper divisors (16152574976764).

21531405333212 is a wasteful number, since it uses less digits than its factorization.

21531405333212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 574425268 (or 574425266 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 35.

Adding to 21531405333212 its reverse (21233350413512), we get a palindrome (42764755746724).

The spelling of 21531405333212 in words is "twenty-one trillion, five hundred thirty-one billion, four hundred five million, three hundred thirty-three thousand, two hundred twelve".