81217058 has 48 divisors (see below), whose sum is σ = 146898360. Its totient is φ = 33357312.

The previous prime is 81217057. The next prime is 81217061. The reversal of 81217058 is 85071218.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 75394489 + 5822569 = 8683^2 + 2413^2 .

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81217057) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 159308 + ... + 159816.

Almost surely, 2^81217058 is an apocalyptic number.

81217058 is a deficient number, since it is larger than the sum of its proper divisors (65681302).

81217058 is a wasteful number, since it uses less digits than its factorization.

81217058 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 579 (or 560 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 81217058 is about 9012.0507100216. The cubic root of 81217058 is about 433.0610100941.

The spelling of 81217058 in words is "eighty-one million, two hundred seventeen thousand, fifty-eight".