82793781 has 36 divisors (see below), whose sum is σ = 139968972. Its totient is φ = 47021184.

The previous prime is 82793779. The next prime is 82793783. The reversal of 82793781 is 18739728.

82793781 is a `hidden beast` number, since 8 + 279 + 378 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (82793779) and next prime (82793783).

It can be written as a sum of positive squares in 2 ways, for example, as 63345681 + 19448100 = 7959^2 + 4410^2 .

It is not a de Polignac number, because 82793781 - 2¹ = 82793779 is a prime.

It is a super-2 number, since 2×82793781² = 13709620344551922, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82793783) 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, 86401 + ... + 87353.

It is an arithmetic number, because the mean of its divisors is an integer number (3888027).

Almost surely, 2^82793781 is an apocalyptic number.

It is an amenable number.

82793781 is a deficient number, since it is larger than the sum of its proper divisors (57175191).

82793781 is a wasteful number, since it uses less digits than its factorization.

82793781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1170 (or 1160 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 82793781 is about 9099.1088025147. The cubic root of 82793781 is about 435.8455057510.

The spelling of 82793781 in words is "eighty-two million, seven hundred ninety-three thousand, seven hundred eighty-one".