2121210101 has 4 divisors (see below), whose sum is σ = 2122398912. Its totient is φ = 2120021292.

The previous prime is 2121210097. The next prime is 2121210107. The reversal of 2121210101 is 1010121212.

2121210101 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 2121210101 - 2² = 2121210097 is a prime.

It is a super-3 number, since 3×2121210101³ (a number of 29 digits) contains 333 as substring.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121210107) 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, 591725 + ... + 595298.

It is an arithmetic number, because the mean of its divisors is an integer number (530599728).

Almost surely, 2^2121210101 is an apocalyptic number.

It is an amenable number.

2121210101 is a deficient number, since it is larger than the sum of its proper divisors (1188811).

2121210101 is a wasteful number, since it uses less digits than its factorization.

2121210101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1188810.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 2121210101 is about 46056.5967153458. The cubic root of 2121210101 is about 1284.8760348147.

Adding to 2121210101 its reverse (1010121212), we get a palindrome (3131331313).

Subtracting from 2121210101 its reverse (1010121212), we obtain a square (1111088889 = 33333²).

It can be divided in two parts, 21212 and 10101, that multiplied together give a palindrome (214262412).

The spelling of 2121210101 in words is "two billion, one hundred twenty-one million, two hundred ten thousand, one hundred one".