101000019991 has 16 divisors (see below), whose sum is σ = 117159598080. Its totient is φ = 86300580960.

The previous prime is 101000019971. The next prime is 101000019997. The reversal of 101000019991 is 199910000101.

It is a cyclic number.

It is not a de Polignac number, because 101000019991 - 2⁵ = 101000019959 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (101000019997) 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, 5439001 + ... + 5457538.

It is an arithmetic number, because the mean of its divisors is an integer number (7322474880).

Almost surely, 2^101000019991 is an apocalyptic number.

101000019991 is a deficient number, since it is larger than the sum of its proper divisors (16159578089).

101000019991 is a wasteful number, since it uses less digits than its factorization.

101000019991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10896606.

The product of its (nonzero) digits is 729, while the sum is 31.

The spelling of 101000019991 in words is "one hundred one billion, nineteen thousand, nine hundred ninety-one".