2101010121 has 24 divisors (see below), whose sum is σ = 3542133504. Its totient is φ = 1175031360.

The previous prime is 2101010083. The next prime is 2101010147. The reversal of 2101010121 is 1210101012.

It is a happy number.

2101010121 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is not a de Polignac number, because 2101010121 - 2⁷ = 2101009993 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

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

It is not an unprimeable number, because it can be changed into a prime (2101010621) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 351820 + ... + 357741.

It is an arithmetic number, because the mean of its divisors is an integer number (147588896).

Almost surely, 2^2101010121 is an apocalyptic number.

2101010121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2101010121 is a deficient number, since it is larger than the sum of its proper divisors (1441123383).

2101010121 is a wasteful number, since it uses less digits than its factorization.

2101010121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 709621 (or 709618 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 2101010121 is about 45836.7769482105. The cubic root of 2101010121 is about 1280.7844558701.

Adding to 2101010121 its reverse (1210101012), we get a palindrome (3311111133).

It can be divided in two parts, 210 and 1010121, that added together give a triangular number (1010331 = T₁₄₂₁).

The spelling of 2101010121 in words is "two billion, one hundred one million, ten thousand, one hundred twenty-one".