3994767521 has 2 divisors, whose sum is σ = 3994767522. Its totient is φ = 3994767520.

The previous prime is 3994767437. The next prime is 3994767527. The reversal of 3994767521 is 1257674993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3753400225 + 241367296 = 61265^2 + 15536^2 .

It is a cyclic number.

It is not a de Polignac number, because 3994767521 - 2¹⁰ = 3994766497 is a prime.

It is not a weakly prime, because it can be changed into another prime (3994767527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1997383760 + 1997383761.

It is an arithmetic number, because the mean of its divisors is an integer number (1997383761).

Almost surely, 2^3994767521 is an apocalyptic number.

It is an amenable number.

3994767521 is a deficient number, since it is larger than the sum of its proper divisors (1).

3994767521 is an equidigital number, since it uses as much as digits as its factorization.

3994767521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2857680, while the sum is 53.

The square root of 3994767521 is about 63204.1732878455. The cubic root of 3994767521 is about 1586.7085797124.

The spelling of 3994767521 in words is "three billion, nine hundred ninety-four million, seven hundred sixty-seven thousand, five hundred twenty-one".