72821687265 has 24 divisors (see below), whose sum is σ = 126236029608. Its totient is φ = 38834611200.

The previous prime is 72821687249. The next prime is 72821687269. The reversal of 72821687265 is 56278612827.

It can be written as a sum of positive squares in 4 ways, for example, as 16955164944 + 55866522321 = 130212^2 + 236361^2 .

It is not a de Polignac number, because 72821687265 - 2⁴ = 72821687249 is a prime.

It is a super-2 number, since 2×72821687265² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (72821687269) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 453115 + ... + 592415.

It is an arithmetic number, because the mean of its divisors is an integer number (5259834567).

Almost surely, 2^72821687265 is an apocalyptic number.

It is an amenable number.

72821687265 is a deficient number, since it is larger than the sum of its proper divisors (53414342343).

72821687265 is a wasteful number, since it uses less digits than its factorization.

72821687265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150929 (or 150926 counting only the distinct ones).

The product of its digits is 4515840, while the sum is 54.

The spelling of 72821687265 in words is "seventy-two billion, eight hundred twenty-one million, six hundred eighty-seven thousand, two hundred sixty-five".