6745538781 has 6 divisors (see below), whose sum is σ = 9743556030. Its totient is φ = 4497025848.

The previous prime is 6745538759. The next prime is 6745538791. The reversal of 6745538781 is 1878355476.

It is a happy number.

6745538781 is a `hidden beast` number, since 6 + 7 + 4 + 553 + 8 + 7 + 81 = 666.

It can be written as a sum of positive squares in only one way, i.e., 3655290681 + 3090248100 = 60459^2 + 55590^2 .

It is not a de Polignac number, because 6745538781 - 2⁶ = 6745538717 is a prime.

It is a super-2 number, since 2×6745538781² = 91004586891949931922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6745538791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 374752146 + ... + 374752163.

It is an arithmetic number, because the mean of its divisors is an integer number (1623926005).

Almost surely, 2^6745538781 is an apocalyptic number.

It is an amenable number.

6745538781 is a deficient number, since it is larger than the sum of its proper divisors (2998017249).

6745538781 is a wasteful number, since it uses less digits than its factorization.

6745538781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 749504315 (or 749504312 counting only the distinct ones).

The product of its digits is 5644800, while the sum is 54.

The square root of 6745538781 is about 82131.2290240442. The cubic root of 6745538781 is about 1889.4651287327.

The spelling of 6745538781 in words is "six billion, seven hundred forty-five million, five hundred thirty-eight thousand, seven hundred eighty-one".