21251123110016 has 16 divisors (see below), whose sum is σ = 42336221820990. Its totient is φ = 10625561554944.

The previous prime is 21251123110001. The next prime is 21251123110057. The reversal of 21251123110016 is 61001132115212.

It can be written as a sum of positive squares in only one way, i.e., 14720236196416 + 6530886913600 = 3836696^2 + 2555560^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is a super-2 number, since 2×21251123110016² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83012199521 + ... + 83012199776.

Almost surely, 2^{21251123110016} is an apocalyptic number.

It is an amenable number.

21251123110016 is a deficient number, since it is larger than the sum of its proper divisors (21085098710974).

21251123110016 is an equidigital number, since it uses as much as digits as its factorization.

21251123110016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166024399311 (or 166024399299 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 26.

Adding to 21251123110016 its reverse (61001132115212), we get a palindrome (82252255225228).

The spelling of 21251123110016 in words is "twenty-one trillion, two hundred fifty-one billion, one hundred twenty-three million, one hundred ten thousand, sixteen".