21224331012161 has 4 divisors (see below), whose sum is σ = 21541112072112. Its totient is φ = 20907549952212.

The previous prime is 21224331012113. The next prime is 21224331012169. The reversal of 21224331012161 is 16121013342212.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21224331012161 - 2³⁴ = 21207151142977 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21224331012169) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 158390529875 + ... + 158390530008.

It is an arithmetic number, because the mean of its divisors is an integer number (5385278018028).

Almost surely, 2^{21224331012161} is an apocalyptic number.

It is an amenable number.

21224331012161 is a deficient number, since it is larger than the sum of its proper divisors (316781059951).

21224331012161 is an equidigital number, since it uses as much as digits as its factorization.

21224331012161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316781059950.

The product of its (nonzero) digits is 3456, while the sum is 29.

Adding to 21224331012161 its reverse (16121013342212), we get a palindrome (37345344354373).

The spelling of 21224331012161 in words is "twenty-one trillion, two hundred twenty-four billion, three hundred thirty-one million, twelve thousand, one hundred sixty-one".