681783511 has 4 divisors (see below), whose sum is σ = 682864624. Its totient is φ = 680702400.

The previous prime is 681783481. The next prime is 681783569. The reversal of 681783511 is 115387186.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 115387186 = 2 ⋅57693593.

It is a cyclic number.

It is not a de Polignac number, because 681783511 - 2¹⁵ = 681750743 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681783581) 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, 539610 + ... + 540871.

It is an arithmetic number, because the mean of its divisors is an integer number (170716156).

Almost surely, 2^681783511 is an apocalyptic number.

681783511 is a deficient number, since it is larger than the sum of its proper divisors (1081113).

681783511 is a wasteful number, since it uses less digits than its factorization.

681783511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1081112.

The product of its digits is 40320, while the sum is 40.

The square root of 681783511 is about 26110.9844892911. The cubic root of 681783511 is about 880.1340666093.

The spelling of 681783511 in words is "six hundred eighty-one million, seven hundred eighty-three thousand, five hundred eleven".