21121126243652 has 6 divisors (see below), whose sum is σ = 36961970926398. Its totient is φ = 10560563121824.

The previous prime is 21121126243643. The next prime is 21121126243699. The reversal of 21121126243652 is 25634262112112.

It can be written as a sum of positive squares in only one way, i.e., 20004097088836 + 1117029154816 = 4472594^2 + 1056896^2 .

It is a super-2 number, since 2×21121126243652² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2640140780453 + ... + 2640140780460.

It is an arithmetic number, because the mean of its divisors is an integer number (6160328487733).

Almost surely, 2^{21121126243652} is an apocalyptic number.

It is an amenable number.

21121126243652 is a deficient number, since it is larger than the sum of its proper divisors (15840844682746).

21121126243652 is a wasteful number, since it uses less digits than its factorization.

21121126243652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5280281560917 (or 5280281560915 counting only the distinct ones).

The product of its digits is 69120, while the sum is 38.

Adding to 21121126243652 its reverse (25634262112112), we get a palindrome (46755388355764).

The spelling of 21121126243652 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred twenty-six million, two hundred forty-three thousand, six hundred fifty-two".