11012121565421 has 4 divisors (see below), whose sum is σ = 11012603455932. Its totient is φ = 11011639674912.

The previous prime is 11012121565387. The next prime is 11012121565441. The reversal of 11012121565421 is 12456512121011.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6323142751396 + 4688978814025 = 2514586^2 + 2165405^2 .

It is a cyclic number.

It is not a de Polignac number, because 11012121565421 - 2¹⁸ = 11012121303277 is a prime.

It is a super-2 number, since 2×11012121565421² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11012121565441) 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, 240910976 + ... + 240956681.

It is an arithmetic number, because the mean of its divisors is an integer number (2753150863983).

Almost surely, 2^{11012121565421} is an apocalyptic number.

It is an amenable number.

11012121565421 is a deficient number, since it is larger than the sum of its proper divisors (481890511).

11012121565421 is an equidigital number, since it uses as much as digits as its factorization.

11012121565421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 481890510.

The product of its (nonzero) digits is 4800, while the sum is 32.

Adding to 11012121565421 its reverse (12456512121011), we get a palindrome (23468633686432).

The spelling of 11012121565421 in words is "eleven trillion, twelve billion, one hundred twenty-one million, five hundred sixty-five thousand, four hundred twenty-one".