75131921 has 2 divisors, whose sum is σ = 75131922. Its totient is φ = 75131920.

The previous prime is 75131911. The next prime is 75131929. The reversal of 75131921 is 12913157.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68293696 + 6838225 = 8264^2 + 2615^2 .

It is a cyclic number.

It is not a de Polignac number, because 75131921 - 2¹⁰ = 75130897 is a prime.

It is not a weakly prime, because it can be changed into another prime (75131929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37565960 + 37565961.

It is an arithmetic number, because the mean of its divisors is an integer number (37565961).

Almost surely, 2^75131921 is an apocalyptic number.

It is an amenable number.

75131921 is a deficient number, since it is larger than the sum of its proper divisors (1).

75131921 is an equidigital number, since it uses as much as digits as its factorization.

75131921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1890, while the sum is 29.

The square root of 75131921 is about 8667.8671540351. The cubic root of 75131921 is about 421.9634466665.

The spelling of 75131921 in words is "seventy-five million, one hundred thirty-one thousand, nine hundred twenty-one".