72305221665 has 16 divisors (see below), whose sum is σ = 115706837376. Its totient is φ = 38556624000.

The previous prime is 72305221663. The next prime is 72305221673. The reversal of 72305221665 is 56612250327.

It is a happy number.

It is not a de Polignac number, because 72305221665 - 2¹ = 72305221663 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (72305221663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 287236 + ... + 476565.

It is an arithmetic number, because the mean of its divisors is an integer number (7231677336).

Almost surely, 2^72305221665 is an apocalyptic number.

It is an amenable number.

72305221665 is a deficient number, since it is larger than the sum of its proper divisors (43401615711).

72305221665 is a wasteful number, since it uses less digits than its factorization.

72305221665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 770120.

The product of its (nonzero) digits is 151200, while the sum is 39.

The spelling of 72305221665 in words is "seventy-two billion, three hundred five million, two hundred twenty-one thousand, six hundred sixty-five".