72356721361 has 4 divisors (see below), whose sum is σ = 75502665792. Its totient is φ = 69210776932.

The previous prime is 72356721347. The next prime is 72356721373. The reversal of 72356721361 is 16312765327.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16312765327 = 17 ⋅959574431.

It is a cyclic number.

It is not a de Polignac number, because 72356721361 - 2⁷ = 72356721233 is a prime.

It is a super-2 number, since 2×72356721361² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72356721961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1572972181 + ... + 1572972226.

It is an arithmetic number, because the mean of its divisors is an integer number (18875666448).

Almost surely, 2^72356721361 is an apocalyptic number.

It is an amenable number.

72356721361 is a deficient number, since it is larger than the sum of its proper divisors (3145944431).

72356721361 is a wasteful number, since it uses less digits than its factorization.

72356721361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3145944430.

The product of its digits is 317520, while the sum is 43.

The spelling of 72356721361 in words is "seventy-two billion, three hundred fifty-six million, seven hundred twenty-one thousand, three hundred sixty-one".