81408356 has 12 divisors (see below), whose sum is σ = 147060480. Its totient is φ = 39391080.

The previous prime is 81408337. The next prime is 81408367. The reversal of 81408356 is 65380418.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 328136 + ... + 328383.

It is an arithmetic number, because the mean of its divisors is an integer number (12255040).

Almost surely, 2^81408356 is an apocalyptic number.

It is an amenable number.

81408356 is a deficient number, since it is larger than the sum of its proper divisors (65652124).

81408356 is a wasteful number, since it uses less digits than its factorization.

81408356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 656554 (or 656552 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 35.

The square root of 81408356 is about 9022.6579232508. The cubic root of 81408356 is about 433.4007529552.

The spelling of 81408356 in words is "eighty-one million, four hundred eight thousand, three hundred fifty-six".