615216422221 has 4 divisors (see below), whose sum is σ = 620660815452. Its totient is φ = 609772028992.

The previous prime is 615216422207. The next prime is 615216422237. The reversal of 615216422221 is 122224612516.

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 347292169225 + 267924252996 = 589315^2 + 517614^2 .

It is a cyclic number.

It is not a de Polignac number, because 615216422221 - 2⁵ = 615216422189 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 (615216422291) 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, 2722196446 + ... + 2722196671.

It is an arithmetic number, because the mean of its divisors is an integer number (155165203863).

Almost surely, 2^615216422221 is an apocalyptic number.

It is an amenable number.

615216422221 is a deficient number, since it is larger than the sum of its proper divisors (5444393231).

615216422221 is a wasteful number, since it uses less digits than its factorization.

615216422221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5444393230.

The product of its digits is 23040, while the sum is 34.

The spelling of 615216422221 in words is "six hundred fifteen billion, two hundred sixteen million, four hundred twenty-two thousand, two hundred twenty-one".