75212561 has 4 divisors (see below), whose sum is σ = 75232692. Its totient is φ = 75192432.

The previous prime is 75212537. The next prime is 75212563. The reversal of 75212561 is 16521257.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16521257 = 283 ⋅58379.

It can be written as a sum of positive squares in 2 ways, for example, as 66912400 + 8300161 = 8180^2 + 2881^2 .

It is a cyclic number.

It is not a de Polignac number, because 75212561 - 2⁶ = 75212497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (75212563) 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, 2630 + ... + 12543.

It is an arithmetic number, because the mean of its divisors is an integer number (18808173).

Almost surely, 2^75212561 is an apocalyptic number.

It is an amenable number.

75212561 is a deficient number, since it is larger than the sum of its proper divisors (20131).

75212561 is a wasteful number, since it uses less digits than its factorization.

75212561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20130.

The product of its digits is 4200, while the sum is 29.

The square root of 75212561 is about 8672.5175698871. The cubic root of 75212561 is about 422.1143588453.

It can be divided in two parts, 7521256 and 1, that added together give a palindrome (7521257).

The spelling of 75212561 in words is "seventy-five million, two hundred twelve thousand, five hundred sixty-one".