81523756 has 48 divisors (see below), whose sum is σ = 158860800. Its totient is φ = 36445248.

The previous prime is 81523751. The next prime is 81523759. The reversal of 81523756 is 65732518.

It is a super-2 number, since 2×81523756² = 13292245584695072, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81523751) 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, 103195 + ... + 103981.

It is an arithmetic number, because the mean of its divisors is an integer number (3309600).

Almost surely, 2^81523756 is an apocalyptic number.

It is an amenable number.

81523756 is a deficient number, since it is larger than the sum of its proper divisors (77337044).

81523756 is a wasteful number, since it uses less digits than its factorization.

81523756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 886 (or 884 counting only the distinct ones).

The product of its digits is 50400, while the sum is 37.

The square root of 81523756 is about 9029.0506699210. The cubic root of 81523756 is about 433.6054446083.

The spelling of 81523756 in words is "eighty-one million, five hundred twenty-three thousand, seven hundred fifty-six".