81751236 has 48 divisors (see below), whose sum is σ = 222652416. Its totient is φ = 22859424.

The previous prime is 81751231. The next prime is 81751237. The reversal of 81751236 is 63215718.

It is a junction number, because it is equal to n+sod(n) for n = 81751197 and 81751206.

It is not an unprimeable number, because it can be changed into a prime (81751231) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6406 + ... + 14301.

It is an arithmetic number, because the mean of its divisors is an integer number (4638592).

Almost surely, 2^81751236 is an apocalyptic number.

It is an amenable number.

81751236 is an abundant number, since it is smaller than the sum of its proper divisors (140901180).

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

81751236 is a wasteful number, since it uses less digits than its factorization.

81751236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20768 (or 20766 counting only the distinct ones).

The product of its digits is 10080, while the sum is 33.

The square root of 81751236 is about 9041.6390107104. The cubic root of 81751236 is about 434.0083740518.

The spelling of 81751236 in words is "eighty-one million, seven hundred fifty-one thousand, two hundred thirty-six".