75756661 has 4 divisors (see below), whose sum is σ = 76051692. Its totient is φ = 75461632.

The previous prime is 75756647. The next prime is 75756677. The reversal of 75756661 is 16665757.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16665757 = 439 ⋅37963.

It can be written as a sum of positive squares in 2 ways, for example, as 72846225 + 2910436 = 8535^2 + 1706^2 .

It is a cyclic number.

It is not a de Polignac number, because 75756661 - 2¹⁹ = 75232373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (75756601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 147130 + ... + 147643.

It is an arithmetic number, because the mean of its divisors is an integer number (19012923).

Almost surely, 2^75756661 is an apocalyptic number.

It is an amenable number.

75756661 is a deficient number, since it is larger than the sum of its proper divisors (295031).

75756661 is a wasteful number, since it uses less digits than its factorization.

75756661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295030.

The product of its digits is 264600, while the sum is 43.

The square root of 75756661 is about 8703.8302488043. The cubic root of 75756661 is about 423.1297956528.

The spelling of 75756661 in words is "seventy-five million, seven hundred fifty-six thousand, six hundred sixty-one".