81570074 has 24 divisors (see below), whose sum is σ = 128643228. Its totient is φ = 38754560.

The previous prime is 81570061. The next prime is 81570079. The reversal of 81570074 is 47007518.

It can be written as a sum of positive squares in 6 ways, for example, as 34304449 + 47265625 = 5857^2 + 6875^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81570074.

It is not an unprimeable number, because it can be changed into a prime (81570079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 595334 + ... + 595470.

Almost surely, 2^81570074 is an apocalyptic number.

81570074 is a deficient number, since it is larger than the sum of its proper divisors (47073154).

81570074 is a wasteful number, since it uses less digits than its factorization.

81570074 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 370 (or 233 counting only the distinct ones).

The product of its (nonzero) digits is 7840, while the sum is 32.

The square root of 81570074 is about 9031.6152486695. The cubic root of 81570074 is about 433.6875471987.

The spelling of 81570074 in words is "eighty-one million, five hundred seventy thousand, seventy-four".