4538921561 has 2 divisors, whose sum is σ = 4538921562. Its totient is φ = 4538921560.

The previous prime is 4538921521. The next prime is 4538921599. The reversal of 4538921561 is 1651298354.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4294311961 + 244609600 = 65531^2 + 15640^2 .

It is a cyclic number.

It is not a de Polignac number, because 4538921561 - 2¹⁰ = 4538920537 is a prime.

It is not a weakly prime, because it can be changed into another prime (4538921521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2269460780 + 2269460781.

It is an arithmetic number, because the mean of its divisors is an integer number (2269460781).

Almost surely, 2^4538921561 is an apocalyptic number.

It is an amenable number.

4538921561 is a deficient number, since it is larger than the sum of its proper divisors (1).

4538921561 is an equidigital number, since it uses as much as digits as its factorization.

4538921561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 259200, while the sum is 44.

The square root of 4538921561 is about 67371.5189156367. The cubic root of 4538921561 is about 1655.7098248489.

The spelling of 4538921561 in words is "four billion, five hundred thirty-eight million, nine hundred twenty-one thousand, five hundred sixty-one".