81916542 has 32 divisors (see below), whose sum is σ = 182626560. Its totient is φ = 27217080.

The previous prime is 81916519. The next prime is 81916553. The reversal of 81916542 is 24561918.

It is a junction number, because it is equal to n+sod(n) for n = 81916497 and 81916506.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15583 + ... + 20165.

It is an arithmetic number, because the mean of its divisors is an integer number (5707080).

Almost surely, 2^81916542 is an apocalyptic number.

81916542 is an abundant number, since it is smaller than the sum of its proper divisors (100710018).

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

81916542 is a wasteful number, since it uses less digits than its factorization.

81916542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4925 (or 4919 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 81916542 is about 9050.7757678555. The cubic root of 81916542 is about 434.3007075952.

The spelling of 81916542 in words is "eighty-one million, nine hundred sixteen thousand, five hundred forty-two".