8538540781 has 4 divisors (see below), whose sum is σ = 8557991200. Its totient is φ = 8519090364.

The previous prime is 8538540767. The next prime is 8538540799. The reversal of 8538540781 is 1870458358.

8538540781 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 8538540781 - 2⁵ = 8538540749 is a prime.

It is a super-2 number, since 2×8538540781² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8538547781) 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, 9724551 + ... + 9725428.

It is an arithmetic number, because the mean of its divisors is an integer number (2139497800).

Almost surely, 2^8538540781 is an apocalyptic number.

It is an amenable number.

8538540781 is a deficient number, since it is larger than the sum of its proper divisors (19450419).

8538540781 is a wasteful number, since it uses less digits than its factorization.

8538540781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19450418.

The product of its (nonzero) digits is 1075200, while the sum is 49.

The square root of 8538540781 is about 92404.2249088211. The cubic root of 8538540781 is about 2043.9074139668.

The spelling of 8538540781 in words is "eight billion, five hundred thirty-eight million, five hundred forty thousand, seven hundred eighty-one".