7155385812 has 72 divisors (see below), whose sum is σ = 18184650120. Its totient is φ = 2372325120.

The previous prime is 7155385781. The next prime is 7155385829. The reversal of 7155385812 is 2185835517.

7155385812 is a `hidden beast` number, since 7 + 1 + 553 + 85 + 8 + 12 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 150700176 + 7004685636 = 12276^2 + 83694^2 .

It is a super-2 number, since 2×7155385812² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9256258 + ... + 9257030.

It is an arithmetic number, because the mean of its divisors is an integer number (252564585).

Almost surely, 2^7155385812 is an apocalyptic number.

It is an amenable number.

7155385812 is an abundant number, since it is smaller than the sum of its proper divisors (11029264308).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7155385812 is a wasteful number, since it uses less digits than its factorization.

7155385812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1833 (or 1828 counting only the distinct ones).

The product of its digits is 336000, while the sum is 45.

The square root of 7155385812 is about 84589.5136054109. The cubic root of 7155385812 is about 1926.9821209084.

The spelling of 7155385812 in words is "seven billion, one hundred fifty-five million, three hundred eighty-five thousand, eight hundred twelve".