72140031221 has 2 divisors, whose sum is σ = 72140031222. Its totient is φ = 72140031220.

The previous prime is 72140031209. The next prime is 72140031251. The reversal of 72140031221 is 12213004127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71636522500 + 503508721 = 267650^2 + 22439^2 .

It is an emirp because it is prime and its reverse (12213004127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72140031221 - 2³⁰ = 71066289397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72140031251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36070015610 + 36070015611.

It is an arithmetic number, because the mean of its divisors is an integer number (36070015611).

Almost surely, 2^72140031221 is an apocalyptic number.

It is an amenable number.

72140031221 is a deficient number, since it is larger than the sum of its proper divisors (1).

72140031221 is an equidigital number, since it uses as much as digits as its factorization.

72140031221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 23.

Adding to 72140031221 its reverse (12213004127), we get a palindrome (84353035348).

The spelling of 72140031221 in words is "seventy-two billion, one hundred forty million, thirty-one thousand, two hundred twenty-one".