75547981 has 2 divisors, whose sum is σ = 75547982. Its totient is φ = 75547980.

The previous prime is 75547973. The next prime is 75547993. The reversal of 75547981 is 18974557.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47817225 + 27730756 = 6915^2 + 5266^2 .

It is a cyclic number.

It is not a de Polignac number, because 75547981 - 2³ = 75547973 is a prime.

It is a super-2 number, since 2×75547981² = 11414994866352722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (75547921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37773990 + 37773991.

It is an arithmetic number, because the mean of its divisors is an integer number (37773991).

Almost surely, 2^75547981 is an apocalyptic number.

It is an amenable number.

75547981 is a deficient number, since it is larger than the sum of its proper divisors (1).

75547981 is an equidigital number, since it uses as much as digits as its factorization.

75547981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 352800, while the sum is 46.

The square root of 75547981 is about 8691.8341562641. The cubic root of 75547981 is about 422.7409192818.

The spelling of 75547981 in words is "seventy-five million, five hundred forty-seven thousand, nine hundred eighty-one".