2101621213 has 4 divisors (see below), whose sum is σ = 2174090940. Its totient is φ = 2029151488.

The previous prime is 2101621189. The next prime is 2101621219. The reversal of 2101621213 is 3121261012.

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 1604643364 + 496977849 = 40058^2 + 22293^2 .

It is a cyclic number.

It is not a de Polignac number, because 2101621213 - 2⁹ = 2101620701 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 (2101621219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36234820 + ... + 36234877.

It is an arithmetic number, because the mean of its divisors is an integer number (543522735).

Almost surely, 2^2101621213 is an apocalyptic number.

It is an amenable number.

2101621213 is a deficient number, since it is larger than the sum of its proper divisors (72469727).

2101621213 is an equidigital number, since it uses as much as digits as its factorization.

2101621213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72469726.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 2101621213 is about 45843.4424209177. The cubic root of 2101621213 is about 1280.9086185696.

Adding to 2101621213 its reverse (3121261012), we get a palindrome (5222882225).

The spelling of 2101621213 in words is "two billion, one hundred one million, six hundred twenty-one thousand, two hundred thirteen".