81712356 has 24 divisors (see below), whose sum is σ = 207995424. Its totient is φ = 24761280.

The previous prime is 81712327. The next prime is 81712357. The reversal of 81712356 is 65321718.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (81712357) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 309385 + ... + 309648.

It is an arithmetic number, because the mean of its divisors is an integer number (8666476).

Almost surely, 2^81712356 is an apocalyptic number.

It is an amenable number.

81712356 is an abundant number, since it is smaller than the sum of its proper divisors (126283068).

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

81712356 is a wasteful number, since it uses less digits than its factorization.

81712356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 619051 (or 619049 counting only the distinct ones).

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

The square root of 81712356 is about 9039.4887023548. The cubic root of 81712356 is about 433.9395599185.

The spelling of 81712356 in words is "eighty-one million, seven hundred twelve thousand, three hundred fifty-six".