81157130 has 8 divisors (see below), whose sum is σ = 146082852. Its totient is φ = 32462848.

The previous prime is 81157129. The next prime is 81157159. The reversal of 81157130 is 3175118.

It can be written as a sum of positive squares in 2 ways, for example, as 81018001 + 139129 = 9001^2 + 373^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 81157130.

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, 4057847 + ... + 4057866.

Almost surely, 2^81157130 is an apocalyptic number.

81157130 is a deficient number, since it is larger than the sum of its proper divisors (64925722).

81157130 is a wasteful number, since it uses less digits than its factorization.

81157130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8115720.

The product of its (nonzero) digits is 840, while the sum is 26.

The square root of 81157130 is about 9008.7252150346. The cubic root of 81157130 is about 432.9544689860.

The spelling of 81157130 in words is "eighty-one million, one hundred fifty-seven thousand, one hundred thirty".