81371630 has 16 divisors (see below), whose sum is σ = 146576304. Its totient is φ = 32524800.

The previous prime is 81371629. The next prime is 81371657. The reversal of 81371630 is 3617318.

It is a junction number, because it is equal to n+sod(n) for n = 81371593 and 81371602.

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, 19205 + ... + 23055.

It is an arithmetic number, because the mean of its divisors is an integer number (9161019).

Almost surely, 2^81371630 is an apocalyptic number.

81371630 is a deficient number, since it is larger than the sum of its proper divisors (65204674).

81371630 is a wasteful number, since it uses less digits than its factorization.

81371630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5971.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 81371630 is about 9020.6224840639. The cubic root of 81371630 is about 433.3355693507.

Adding to 81371630 its reverse (3617318), we get a palindrome (84988948).

The spelling of 81371630 in words is "eighty-one million, three hundred seventy-one thousand, six hundred thirty".