21255253613212 has 24 divisors (see below), whose sum is σ = 39546279906336. Its totient is φ = 9973753128768.

The previous prime is 21255253613201. The next prime is 21255253613219. The reversal of 21255253613212 is 21231635255212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255253613219) 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, 2179574043 + ... + 2179583794.

It is an arithmetic number, because the mean of its divisors is an integer number (1647761662764).

Almost surely, 2^{21255253613212} is an apocalyptic number.

It is an amenable number.

21255253613212 is a deficient number, since it is larger than the sum of its proper divisors (18291026293124).

21255253613212 is a wasteful number, since it uses less digits than its factorization.

21255253613212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4359157917 (or 4359157915 counting only the distinct ones).

The product of its digits is 216000, while the sum is 40.

Adding to 21255253613212 its reverse (21231635255212), we get a palindrome (42486888868424).

The spelling of 21255253613212 in words is "twenty-one trillion, two hundred fifty-five billion, two hundred fifty-three million, six hundred thirteen thousand, two hundred twelve".