2101010101 has 4 divisors (see below), whose sum is σ = 2211589600. Its totient is φ = 1990430604.

The previous prime is 2101010083. The next prime is 2101010147. The reversal of 2101010101 is 1010101012.

2101010101 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2101010101 - 2⁵ = 2101010069 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

2101010101 is a modest number, since divided by 10101 gives 2101 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101017101) 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, 55289721 + ... + 55289758.

It is an arithmetic number, because the mean of its divisors is an integer number (552897400).

Almost surely, 2^2101010101 is an apocalyptic number.

It is an amenable number.

2101010101 is a deficient number, since it is larger than the sum of its proper divisors (110579499).

2101010101 is a wasteful number, since it uses less digits than its factorization.

2101010101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110579498.

The product of its (nonzero) digits is 2, while the sum is 7.

The square root of 2101010101 is about 45836.7767300451. The cubic root of 2101010101 is about 1280.7844518060.

Adding to 2101010101 its reverse (1010101012), we get a palindrome (3111111113).

It can be divided in two parts, 2 and 101010101, that multiplied together give a palindrome (202020202).

The spelling of 2101010101 in words is "two billion, one hundred one million, ten thousand, one hundred one".