684140755 has 4 divisors (see below), whose sum is σ = 820968912. Its totient is φ = 547312600.

The previous prime is 684140731. The next prime is 684140791. The reversal of 684140755 is 557041486.

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

It is not a de Polignac number, because 684140755 - 2⁷ = 684140627 is a prime.

It is a super-3 number, since 3×684140755³ (a number of 27 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68414071 + ... + 68414080.

It is an arithmetic number, because the mean of its divisors is an integer number (205242228).

Almost surely, 2^684140755 is an apocalyptic number.

684140755 is a deficient number, since it is larger than the sum of its proper divisors (136828157).

684140755 is a wasteful number, since it uses less digits than its factorization.

684140755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136828156.

The product of its (nonzero) digits is 134400, while the sum is 40.

The square root of 684140755 is about 26156.0844737893. The cubic root of 684140755 is about 881.1472446627.

The spelling of 684140755 in words is "six hundred eighty-four million, one hundred forty thousand, seven hundred fifty-five".