72706073221 has 4 divisors (see below), whose sum is σ = 72710607744. Its totient is φ = 72701538700.

The previous prime is 72706073213. The next prime is 72706073243. The reversal of 72706073221 is 12237060727.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 72706073221 - 2³ = 72706073213 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 (72706073821) 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, 2243125 + ... + 2275306.

It is an arithmetic number, because the mean of its divisors is an integer number (18177651936).

Almost surely, 2^72706073221 is an apocalyptic number.

It is an amenable number.

72706073221 is a deficient number, since it is larger than the sum of its proper divisors (4534523).

72706073221 is a wasteful number, since it uses less digits than its factorization.

72706073221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4534522.

The product of its (nonzero) digits is 49392, while the sum is 37.

The spelling of 72706073221 in words is "seventy-two billion, seven hundred six million, seventy-three thousand, two hundred twenty-one".