21253236033155 has 64 divisors (see below), whose sum is σ = 29953566720000. Its totient is φ = 14175781982208.

The previous prime is 21253236033149. The next prime is 21253236033157. The reversal of 21253236033155 is 55133063235212.

It is not a de Polignac number, because 21253236033155 - 2¹² = 21253236029059 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21253236033157) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1207630046 + ... + 1207647644.

It is an arithmetic number, because the mean of its divisors is an integer number (468024480000).

Almost surely, 2^{21253236033155} is an apocalyptic number.

21253236033155 is a deficient number, since it is larger than the sum of its proper divisors (8700330686845).

21253236033155 is a wasteful number, since it uses less digits than its factorization.

21253236033155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23796.

The product of its (nonzero) digits is 486000, while the sum is 41.

Adding to 21253236033155 its reverse (55133063235212), we get a palindrome (76386299268367).

The spelling of 21253236033155 in words is "twenty-one trillion, two hundred fifty-three billion, two hundred thirty-six million, thirty-three thousand, one hundred fifty-five".