21253042551206 has 16 divisors (see below), whose sum is σ = 32748916202640. Its totient is φ = 10336872984480.

The previous prime is 21253042551203. The next prime is 21253042551227. The reversal of 21253042551206 is 60215524035212.

It is a super-2 number, since 2×21253042551206² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21253042551206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21253042551203) 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, 33643460 + ... + 34269351.

It is an arithmetic number, because the mean of its divisors is an integer number (2046807262665).

Almost surely, 2^{21253042551206} is an apocalyptic number.

21253042551206 is a deficient number, since it is larger than the sum of its proper divisors (11495873651434).

21253042551206 is a wasteful number, since it uses less digits than its factorization.

21253042551206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67917079.

The product of its (nonzero) digits is 144000, while the sum is 38.

Adding to 21253042551206 its reverse (60215524035212), we get a palindrome (81468566586418).

The spelling of 21253042551206 in words is "twenty-one trillion, two hundred fifty-three billion, forty-two million, five hundred fifty-one thousand, two hundred six".