81941312 has 14 divisors (see below), whose sum is σ = 162602418. Its totient is φ = 40970624.

The previous prime is 81941303. The next prime is 81941369. The reversal of 81941312 is 21314918.

It can be written as a sum of positive squares in only one way, i.e., 47554816 + 34386496 = 6896^2 + 5864^2 .

It is a super-2 number, since 2×81941312² = 13428757224562688, 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 as a sum of consecutive naturals, namely, 640103 + ... + 640230.

Almost surely, 2^81941312 is an apocalyptic number.

It is an amenable number.

81941312 is a deficient number, since it is larger than the sum of its proper divisors (80661106).

81941312 is a wasteful number, since it uses less digits than its factorization.

81941312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1280345 (or 1280335 counting only the distinct ones).

The product of its digits is 1728, while the sum is 29.

The square root of 81941312 is about 9052.1440554158. The cubic root of 81941312 is about 434.3444779340.

The spelling of 81941312 in words is "eighty-one million, nine hundred forty-one thousand, three hundred twelve".