101110021721 has 2 divisors, whose sum is σ = 101110021722. Its totient is φ = 101110021720.

The previous prime is 101110021697. The next prime is 101110021741. The reversal of 101110021721 is 127120011101.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65864089600 + 35245932121 = 256640^2 + 187739^2 .

It is an emirp because it is prime and its reverse (127120011101) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 101110021721 - 2²⁶ = 101042912857 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 101110021721.

It is not a weakly prime, because it can be changed into another prime (101110021741) by changing a digit.

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, 50555010860 + 50555010861.

It is an arithmetic number, because the mean of its divisors is an integer number (50555010861).

Almost surely, 2^101110021721 is an apocalyptic number.

It is an amenable number.

101110021721 is a deficient number, since it is larger than the sum of its proper divisors (1).

101110021721 is an equidigital number, since it uses as much as digits as its factorization.

101110021721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28, while the sum is 17.

Adding to 101110021721 its reverse (127120011101), we get a palindrome (228230032822).

The spelling of 101110021721 in words is "one hundred one billion, one hundred ten million, twenty-one thousand, seven hundred twenty-one".