81371070 has 48 divisors (see below), whose sum is σ = 230800752. Its totient is φ = 19726080.

The previous prime is 81371051. The next prime is 81371077. The reversal of 81371070 is 7017318.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81371077) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 40107 + ... + 42086.

It is an arithmetic number, because the mean of its divisors is an integer number (4808349).

Almost surely, 2^81371070 is an apocalyptic number.

81371070 is an abundant number, since it is smaller than the sum of its proper divisors (149429682).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81371070 is a wasteful number, since it uses less digits than its factorization.

81371070 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82217 (or 82214 counting only the distinct ones).

The product of its (nonzero) digits is 1176, while the sum is 27.

The square root of 81371070 is about 9020.5914440241. The cubic root of 81371070 is about 433.3345752759.

Adding to 81371070 its reverse (7017318), we get a palindrome (88388388).

The spelling of 81371070 in words is "eighty-one million, three hundred seventy-one thousand, seventy".