72121726167217 has 4 divisors (see below), whose sum is σ = 73034659409920. Its totient is φ = 71208792924516.

The previous prime is 72121726167181. The next prime is 72121726167349. The reversal of 72121726167217 is 71276162712127.

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 72121726167217 - 2¹⁹ = 72121725642929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72121726167817) 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, 456466621233 + ... + 456466621390.

It is an arithmetic number, because the mean of its divisors is an integer number (18258664852480).

Almost surely, 2^{72121726167217} is an apocalyptic number.

It is an amenable number.

72121726167217 is a deficient number, since it is larger than the sum of its proper divisors (912933242703).

72121726167217 is an equidigital number, since it uses as much as digits as its factorization.

72121726167217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 912933242702.

The product of its digits is 1382976, while the sum is 52.

The spelling of 72121726167217 in words is "seventy-two trillion, one hundred twenty-one billion, seven hundred twenty-six million, one hundred sixty-seven thousand, two hundred seventeen".