75566921 has 4 divisors (see below), whose sum is σ = 80012052. Its totient is φ = 71121792.

The previous prime is 75566917. The next prime is 75566927. The reversal of 75566921 is 12966557.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 24601600 + 50965321 = 4960^2 + 7139^2 .

It is a cyclic number.

It is not a de Polignac number, because 75566921 - 2² = 75566917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (75566927) 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, 2222540 + ... + 2222573.

It is an arithmetic number, because the mean of its divisors is an integer number (20003013).

Almost surely, 2^75566921 is an apocalyptic number.

It is an amenable number.

75566921 is a deficient number, since it is larger than the sum of its proper divisors (4445131).

75566921 is a wasteful number, since it uses less digits than its factorization.

75566921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4445130.

The product of its digits is 113400, while the sum is 41.

The square root of 75566921 is about 8692.9236163675. The cubic root of 75566921 is about 422.7762436055.

It can be divided in two parts, 755 and 66921, that added together give a palindrome (67676).

The spelling of 75566921 in words is "seventy-five million, five hundred sixty-six thousand, nine hundred twenty-one".