81382072 has 8 divisors (see below), whose sum is σ = 152591400. Its totient is φ = 40691032.

The previous prime is 81382057. The next prime is 81382097. The reversal of 81382072 is 27028318.

It is a tau number, because it is divible by the number of its divisors (8).

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, 5086372 + ... + 5086387.

It is an arithmetic number, because the mean of its divisors is an integer number (19073925).

Almost surely, 2^81382072 is an apocalyptic number.

It is an amenable number.

81382072 is a deficient number, since it is larger than the sum of its proper divisors (71209328).

81382072 is a wasteful number, since it uses less digits than its factorization.

81382072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10172765 (or 10172761 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 81382072 is about 9021.2012503879. The cubic root of 81382072 is about 433.3541044613.

The spelling of 81382072 in words is "eighty-one million, three hundred eighty-two thousand, seventy-two".