75981645 has 40 divisors (see below), whose sum is σ = 139403616. Its totient is φ = 39572064.

The previous prime is 75981643. The next prime is 75981649. The reversal of 75981645 is 54618957.

75981645 is a `hidden beast` number, since 7 + 598 + 16 + 45 = 666.

It is not a de Polignac number, because 75981645 - 2¹ = 75981643 is a prime.

It is a super-3 number, since 3×75981645³ (a number of 25 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 75981645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (75981641) 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 39 ways as a sum of consecutive naturals, for example, 15234 + ... + 19596.

Almost surely, 2^75981645 is an apocalyptic number.

It is an amenable number.

75981645 is a deficient number, since it is larger than the sum of its proper divisors (63421971).

75981645 is a wasteful number, since it uses less digits than its factorization.

75981645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4423 (or 4414 counting only the distinct ones).

The product of its digits is 302400, while the sum is 45.

The square root of 75981645 is about 8716.7450920627. The cubic root of 75981645 is about 423.5482554422.

The spelling of 75981645 in words is "seventy-five million, nine hundred eighty-one thousand, six hundred forty-five".