81000244 has 24 divisors (see below), whose sum is σ = 152899208. Its totient is φ = 37324800.

The previous prime is 81000233. The next prime is 81000263. The reversal of 81000244 is 44200018.

It can be written as a sum of positive squares in 4 ways, for example, as 2890000 + 78110244 = 1700^2 + 8838^2 .

It is a super-2 number, since 2×81000244² = 13122079056119072, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61804 + ... + 63100.

Almost surely, 2^81000244 is an apocalyptic number.

It is an amenable number.

81000244 is a deficient number, since it is larger than the sum of its proper divisors (71898964).

81000244 is a wasteful number, since it uses less digits than its factorization.

81000244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2515 (or 2513 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 81000244 is about 9000.0135555453. The cubic root of 81000244 is about 432.6753055472.

The spelling of 81000244 in words is "eighty-one million, two hundred forty-four", and thus it is an aban number.