6815131945 has 16 divisors (see below), whose sum is σ = 8613138240. Its totient is φ = 5162422464.

The previous prime is 6815131943. The next prime is 6815131951. The reversal of 6815131945 is 5491315186.

It is a cyclic number.

It is not a de Polignac number, because 6815131945 - 2¹ = 6815131943 is a prime.

It is a super-3 number, since 3×6815131945³ (a number of 30 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (6815131943) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 171754 + ... + 207676.

It is an arithmetic number, because the mean of its divisors is an integer number (538321140).

Almost surely, 2^6815131945 is an apocalyptic number.

It is an amenable number.

6815131945 is a deficient number, since it is larger than the sum of its proper divisors (1798006295).

6815131945 is a wasteful number, since it uses less digits than its factorization.

6815131945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37944.

The product of its digits is 129600, while the sum is 43.

The square root of 6815131945 is about 82553.8124195364. The cubic root of 6815131945 is about 1895.9407284469.

The spelling of 6815131945 in words is "six billion, eight hundred fifteen million, one hundred thirty-one thousand, nine hundred forty-five".