100388721991 has 2 divisors, whose sum is σ = 100388721992. Its totient is φ = 100388721990.

The previous prime is 100388721977. The next prime is 100388722039. The reversal of 100388721991 is 199127883001.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 100388721991 - 2⁵ = 100388721959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100382721991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50194360995 + 50194360996.

It is an arithmetic number, because the mean of its divisors is an integer number (50194360996).

Almost surely, 2^100388721991 is an apocalyptic number.

100388721991 is a deficient number, since it is larger than the sum of its proper divisors (1).

100388721991 is an equidigital number, since it uses as much as digits as its factorization.

100388721991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 217728, while the sum is 49.

The spelling of 100388721991 in words is "one hundred billion, three hundred eighty-eight million, seven hundred twenty-one thousand, nine hundred ninety-one".