206851332681 has 36 divisors (see below), whose sum is σ = 348280575552. Its totient is φ = 117957927024.

The previous prime is 206851332661. The next prime is 206851332689. The reversal of 206851332681 is 186233158602.

206851332681 is a `hidden beast` number, since 20 + 6 + 8 + 513 + 32 + 6 + 81 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-206851332681 is a prime.

It is a super-2 number, since 2×206851332681² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (206851332689) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 266805 + ... + 696338.

It is an arithmetic number, because the mean of its divisors is an integer number (9674460432).

Almost surely, 2^206851332681 is an apocalyptic number.

206851332681 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

206851332681 is a deficient number, since it is larger than the sum of its proper divisors (141429242871).

206851332681 is a wasteful number, since it uses less digits than its factorization.

206851332681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 963650 (or 963640 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The spelling of 206851332681 in words is "two hundred six billion, eight hundred fifty-one million, three hundred thirty-two thousand, six hundred eighty-one".