215443370221 has 4 divisors (see below), whose sum is σ = 215521973244. Its totient is φ = 215364767200.

The previous prime is 215443370201. The next prime is 215443370287. The reversal of 215443370221 is 122073344512.

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 91739928996 + 123703441225 = 302886^2 + 351715^2 .

It is a cyclic number.

It is not a de Polignac number, because 215443370221 - 2⁵ = 215443370189 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 (215443370201) 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, 39297400 + ... + 39302881.

It is an arithmetic number, because the mean of its divisors is an integer number (53880493311).

Almost surely, 2^215443370221 is an apocalyptic number.

It is an amenable number.

215443370221 is a deficient number, since it is larger than the sum of its proper divisors (78603023).

215443370221 is an equidigital number, since it uses as much as digits as its factorization.

215443370221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78603022.

The product of its (nonzero) digits is 40320, while the sum is 34.

The spelling of 215443370221 in words is "two hundred fifteen billion, four hundred forty-three million, three hundred seventy thousand, two hundred twenty-one".