862181661 has 32 divisors (see below), whose sum is σ = 1303981056. Its totient is φ = 502128000.

The previous prime is 862181653. The next prime is 862181669. The reversal of 862181661 is 166181268.

It is an interprime number because it is at equal distance from previous prime (862181653) and next prime (862181669).

It is not a de Polignac number, because 862181661 - 2³ = 862181653 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (862181669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 85896 + ... + 95406.

It is an arithmetic number, because the mean of its divisors is an integer number (40749408).

Almost surely, 2^862181661 is an apocalyptic number.

It is an amenable number.

862181661 is a deficient number, since it is larger than the sum of its proper divisors (441799395).

862181661 is a wasteful number, since it uses less digits than its factorization.

862181661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9633.

The product of its digits is 27648, while the sum is 39.

The square root of 862181661 is about 29362.9300479363. The cubic root of 862181661 is about 951.7720060647.

The spelling of 862181661 in words is "eight hundred sixty-two million, one hundred eighty-one thousand, six hundred sixty-one".