81017478 has 24 divisors (see below), whose sum is σ = 185864328. Its totient is φ = 25417152.

The previous prime is 81017473. The next prime is 81017479. The reversal of 81017478 is 87471018.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81017473) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 132076 + ... + 132687.

It is an arithmetic number, because the mean of its divisors is an integer number (7744347).

Almost surely, 2^81017478 is an apocalyptic number.

81017478 is an abundant number, since it is smaller than the sum of its proper divisors (104846850).

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

81017478 is a wasteful number, since it uses less digits than its factorization.

81017478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264788 (or 264785 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 36.

The square root of 81017478 is about 9000.9709476256. The cubic root of 81017478 is about 432.7059893948.

The spelling of 81017478 in words is "eighty-one million, seventeen thousand, four hundred seventy-eight".