20191920101 has 4 divisors (see below), whose sum is σ = 20391840204. Its totient is φ = 19992000000.

The previous prime is 20191920061. The next prime is 20191920131. The reversal of 20191920101 is 10102919102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15253485025 + 4938435076 = 123505^2 + 70274^2 .

It is a cyclic number.

It is not a de Polignac number, because 20191920101 - 2¹⁴ = 20191903717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20191920131) 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 in 3 ways as a sum of consecutive naturals, for example, 99959900 + ... + 99960101.

It is an arithmetic number, because the mean of its divisors is an integer number (5097960051).

Almost surely, 2^20191920101 is an apocalyptic number.

It is an amenable number.

20191920101 is a deficient number, since it is larger than the sum of its proper divisors (199920103).

20191920101 is a wasteful number, since it uses less digits than its factorization.

20191920101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199920102.

The product of its (nonzero) digits is 324, while the sum is 26.

The spelling of 20191920101 in words is "twenty billion, one hundred ninety-one million, nine hundred twenty thousand, one hundred one".