6143557781 has 4 divisors (see below), whose sum is σ = 6169049964. Its totient is φ = 6118065600.

The previous prime is 6143557747. The next prime is 6143557789. The reversal of 6143557781 is 1877553416.

6143557781 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4051959025 + 2091598756 = 63655^2 + 45734^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6143557781 is a prime.

It is a super-2 number, since 2×6143557781² = 75486604416971287922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6143557789) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12745730 + ... + 12746211.

It is an arithmetic number, because the mean of its divisors is an integer number (1542262491).

Almost surely, 2^6143557781 is an apocalyptic number.

It is an amenable number.

6143557781 is a deficient number, since it is larger than the sum of its proper divisors (25492183).

6143557781 is a wasteful number, since it uses less digits than its factorization.

6143557781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25492182.

The product of its digits is 705600, while the sum is 47.

The square root of 6143557781 is about 78380.8508565708. The cubic root of 6143557781 is about 1831.4988448099.

The spelling of 6143557781 in words is "six billion, one hundred forty-three million, five hundred fifty-seven thousand, seven hundred eighty-one".