75645981 has 20 divisors (see below), whose sum is σ = 114111712. Its totient is φ = 49935528.

The previous prime is 75645979. The next prime is 75645989. The reversal of 75645981 is 18954657.

75645981 is a `hidden beast` number, since 7 + 56 + 4 + 598 + 1 = 666.

It is not a de Polignac number, because 75645981 - 2¹ = 75645979 is a prime.

It is a super-2 number, since 2×75645981² = 11444628882904722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (75645989) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3810 + ... + 12876.

Almost surely, 2^75645981 is an apocalyptic number.

It is an amenable number.

75645981 is a deficient number, since it is larger than the sum of its proper divisors (38465731).

75645981 is a wasteful number, since it uses less digits than its factorization.

75645981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9182 (or 9173 counting only the distinct ones).

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

The square root of 75645981 is about 8697.4698044891. The cubic root of 75645981 is about 422.9236319053.

The spelling of 75645981 in words is "seventy-five million, six hundred forty-five thousand, nine hundred eighty-one".