221305770640 has 20 divisors (see below), whose sum is σ = 514535916924. Its totient is φ = 88522308224.

The previous prime is 221305770617. The next prime is 221305770649. The reversal of 221305770640 is 46077503122.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 173069312256 + 48236458384 = 416016^2 + 219628^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a self number, because there is not a number n which added to its sum of digits gives 221305770640.

It is not an unprimeable number, because it can be changed into a prime (221305770649) 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, 1383160987 + ... + 1383161146.

Almost surely, 2^221305770640 is an apocalyptic number.

221305770640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221305770640 is an abundant number, since it is smaller than the sum of its proper divisors (293230146284).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221305770640 is a wasteful number, since it uses less digits than its factorization.

221305770640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2766322146 (or 2766322140 counting only the distinct ones).

The product of its (nonzero) digits is 70560, while the sum is 37.

The spelling of 221305770640 in words is "two hundred twenty-one billion, three hundred five million, seven hundred seventy thousand, six hundred forty".