72061551217 has 4 divisors (see below), whose sum is σ = 72071737920. Its totient is φ = 72051364516.

The previous prime is 72061551179. The next prime is 72061551293. The reversal of 72061551217 is 71215516027.

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 72061551217 - 2²³ = 72053162609 is a prime.

It is a super-4 number, since 4×72061551217⁴ (a number of 45 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72061551817) 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, 5082733 + ... + 5096890.

It is an arithmetic number, because the mean of its divisors is an integer number (18017934480).

Almost surely, 2^72061551217 is an apocalyptic number.

It is an amenable number.

72061551217 is a deficient number, since it is larger than the sum of its proper divisors (10186703).

72061551217 is a wasteful number, since it uses less digits than its factorization.

72061551217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10186702.

The product of its (nonzero) digits is 29400, while the sum is 37.

The spelling of 72061551217 in words is "seventy-two billion, sixty-one million, five hundred fifty-one thousand, two hundred seventeen".