2101191901 has 4 divisors (see below), whose sum is σ = 2101370812. Its totient is φ = 2101012992.

The previous prime is 2101191899. The next prime is 2101191907. The reversal of 2101191901 is 1091911012.

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 521208900 + 1579983001 = 22830^2 + 39749^2 .

It is a cyclic number.

It is not a de Polignac number, because 2101191901 - 2¹ = 2101191899 is a prime.

It is a super-3 number, since 3×2101191901³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101191907) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70500 + ... + 95773.

It is an arithmetic number, because the mean of its divisors is an integer number (525342703).

Almost surely, 2^2101191901 is an apocalyptic number.

It is an amenable number.

2101191901 is a deficient number, since it is larger than the sum of its proper divisors (178911).

2101191901 is a wasteful number, since it uses less digits than its factorization.

2101191901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178910.

The product of its (nonzero) digits is 162, while the sum is 25.

The square root of 2101191901 is about 45838.7598108849. The cubic root of 2101191901 is about 1280.8213927513.

The spelling of 2101191901 in words is "two billion, one hundred one million, one hundred ninety-one thousand, nine hundred one".