81015542 has 8 divisors (see below), whose sum is σ = 121953576. Its totient is φ = 40364352.

The previous prime is 81015511. The next prime is 81015547. The reversal of 81015542 is 24551018.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81015547) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71003 + ... + 72134.

It is an arithmetic number, because the mean of its divisors is an integer number (15244197).

Almost surely, 2^81015542 is an apocalyptic number.

81015542 is a deficient number, since it is larger than the sum of its proper divisors (40938034).

81015542 is a wasteful number, since it uses less digits than its factorization.

81015542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143422.

The product of its (nonzero) digits is 1600, while the sum is 26.

The square root of 81015542 is about 9000.8634030297. The cubic root of 81015542 is about 432.7025427087.

The spelling of 81015542 in words is "eighty-one million, fifteen thousand, five hundred forty-two".