21100442310521 has 16 divisors (see below), whose sum is σ = 24123967776000. Its totient is φ = 18079212072768.

The previous prime is 21100442310457. The next prime is 21100442310539. The reversal of 21100442310521 is 12501324400112.

It is a happy number.

It is not a de Polignac number, because 21100442310521 - 2⁶ = 21100442310457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21100442310581) 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, 277639595 + ... + 277715583.

It is an arithmetic number, because the mean of its divisors is an integer number (1507747986000).

Almost surely, 2^{21100442310521} is an apocalyptic number.

It is an amenable number.

21100442310521 is a deficient number, since it is larger than the sum of its proper divisors (3023525465479).

21100442310521 is a wasteful number, since it uses less digits than its factorization.

21100442310521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90568.

The product of its (nonzero) digits is 1920, while the sum is 26.

Adding to 21100442310521 its reverse (12501324400112), we get a palindrome (33601766710633).

The spelling of 21100442310521 in words is "twenty-one trillion, one hundred billion, four hundred forty-two million, three hundred ten thousand, five hundred twenty-one".