21553231011213 has 16 divisors (see below), whose sum is σ = 31350961506816. Its totient is φ = 13062227870640.

The previous prime is 21553231011211. The next prime is 21553231011251. The reversal of 21553231011213 is 31211013235512.

It is a happy number.

It is not a de Polignac number, because 21553231011213 - 2¹ = 21553231011211 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21553231011211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7105545 + ... + 9674462.

It is an arithmetic number, because the mean of its divisors is an integer number (1959435094176).

Almost surely, 2^{21553231011213} is an apocalyptic number.

It is an amenable number.

21553231011213 is a deficient number, since it is larger than the sum of its proper divisors (9797730495603).

21553231011213 is a wasteful number, since it uses less digits than its factorization.

21553231011213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16818944.

The product of its (nonzero) digits is 5400, while the sum is 30.

Adding to 21553231011213 its reverse (31211013235512), we get a palindrome (52764244246725).

The spelling of 21553231011213 in words is "twenty-one trillion, five hundred fifty-three billion, two hundred thirty-one million, eleven thousand, two hundred thirteen".