3987794221 has 2 divisors, whose sum is σ = 3987794222. Its totient is φ = 3987794220.

The previous prime is 3987794207. The next prime is 3987794231. The reversal of 3987794221 is 1224977893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3959555625 + 28238596 = 62925^2 + 5314^2 .

It is a cyclic number.

It is not a de Polignac number, because 3987794221 - 2⁷ = 3987794093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3987794231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1993897110 + 1993897111.

It is an arithmetic number, because the mean of its divisors is an integer number (1993897111).

Almost surely, 2^3987794221 is an apocalyptic number.

It is an amenable number.

3987794221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3987794221 is an equidigital number, since it uses as much as digits as its factorization.

3987794221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1524096, while the sum is 52.

The square root of 3987794221 is about 63148.9843227902. The cubic root of 3987794221 is about 1585.7847846662.

The spelling of 3987794221 in words is "three billion, nine hundred eighty-seven million, seven hundred ninety-four thousand, two hundred twenty-one".