72420374305721 has 8 divisors (see below), whose sum is σ = 78043833506184. Its totient is φ = 66804438130560.

The previous prime is 72420374305627. The next prime is 72420374305733. The reversal of 72420374305721 is 12750347302427.

It can be written as a sum of positive squares in 4 ways, for example, as 3468027205696 + 68952347100025 = 1862264^2 + 8303755^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-72420374305721 is a prime.

It is a super-2 number, since 2×72420374305721² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (72420374305621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1880736326 + ... + 1880774831.

It is an arithmetic number, because the mean of its divisors is an integer number (9755479188273).

Almost surely, 2^{72420374305721} is an apocalyptic number.

It is an amenable number.

72420374305721 is a deficient number, since it is larger than the sum of its proper divisors (5623459200463).

72420374305721 is a wasteful number, since it uses less digits than its factorization.

72420374305721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3761512651.

The product of its (nonzero) digits is 1975680, while the sum is 47.

The spelling of 72420374305721 in words is "seventy-two trillion, four hundred twenty billion, three hundred seventy-four million, three hundred five thousand, seven hundred twenty-one".