81720376 has 32 divisors (see below), whose sum is σ = 159555600. Its totient is φ = 39191040.

The previous prime is 81720313. The next prime is 81720409. The reversal of 81720376 is 67302718.

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, 36736 + ... + 38896.

Almost surely, 2^81720376 is an apocalyptic number.

It is an amenable number.

81720376 is a deficient number, since it is larger than the sum of its proper divisors (77835224).

81720376 is a wasteful number, since it uses less digits than its factorization.

81720376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2359 (or 2355 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 34.

The square root of 81720376 is about 9039.9323006315. The cubic root of 81720376 is about 433.9537563900.

The spelling of 81720376 in words is "eighty-one million, seven hundred twenty thousand, three hundred seventy-six".