2101222421 has 4 divisors (see below), whose sum is σ = 2102046732. Its totient is φ = 2100398112.

The previous prime is 2101222393. The next prime is 2101222469. The reversal of 2101222421 is 1242221012.

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 834574321 + 1266648100 = 28889^2 + 35590^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2101222421 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2101222421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101222021) 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, 408320 + ... + 413433.

It is an arithmetic number, because the mean of its divisors is an integer number (525511683).

Almost surely, 2^2101222421 is an apocalyptic number.

It is an amenable number.

2101222421 is a deficient number, since it is larger than the sum of its proper divisors (824311).

2101222421 is an equidigital number, since it uses as much as digits as its factorization.

2101222421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 824310.

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 2101222421 is about 45839.0927157159. The cubic root of 2101222421 is about 1280.8275940697.

Adding to 2101222421 its reverse (1242221012), we get a palindrome (3343443433).

The spelling of 2101222421 in words is "two billion, one hundred one million, two hundred twenty-two thousand, four hundred twenty-one".