82442781 has 12 divisors (see below), whose sum is σ = 121037020. Its totient is φ = 54060480.

The previous prime is 82442777. The next prime is 82442783. The reversal of 82442781 is 18724428.

It can be written as a sum of positive squares in 2 ways, for example, as 44435556 + 38007225 = 6666^2 + 6165^2 .

It is not a de Polignac number, because 82442781 - 2² = 82442777 is a prime.

It is a super-2 number, since 2×82442781² = 13593624278027922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82442783) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 74536 + ... + 75633.

Almost surely, 2^82442781 is an apocalyptic number.

It is an amenable number.

82442781 is a deficient number, since it is larger than the sum of its proper divisors (38594239).

82442781 is a wasteful number, since it uses less digits than its factorization.

82442781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150236 (or 150233 counting only the distinct ones).

The product of its digits is 28672, while the sum is 36.

The square root of 82442781 is about 9079.8007136721. The cubic root of 82442781 is about 435.2287184053.

It can be divided in two parts, 8244 and 2781, that added together give a square (11025 = 105²).

The spelling of 82442781 in words is "eighty-two million, four hundred forty-two thousand, seven hundred eighty-one".