101001009993721 has 2 divisors, whose sum is σ = 101001009993722. Its totient is φ = 101001009993720.

The previous prime is 101001009993673. The next prime is 101001009993787. The reversal of 101001009993721 is 127399900100101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84638896003600 + 16362113990121 = 9199940^2 + 4045011^2 .

It is an emirp because it is prime and its reverse (127399900100101) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 101001009993721 - 2⁹ = 101001009993209 is a prime.

It is not a weakly prime, because it can be changed into another prime (101001009393721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50500504996860 + 50500504996861.

It is an arithmetic number, because the mean of its divisors is an integer number (50500504996861).

Almost surely, 2^{101001009993721} is an apocalyptic number.

It is an amenable number.

101001009993721 is a deficient number, since it is larger than the sum of its proper divisors (1).

101001009993721 is an equidigital number, since it uses as much as digits as its factorization.

101001009993721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30618, while the sum is 43.

The spelling of 101001009993721 in words is "one hundred one trillion, one billion, nine million, nine hundred ninety-three thousand, seven hundred twenty-one".