1198730821 has 2 divisors, whose sum is σ = 1198730822. Its totient is φ = 1198730820.

The previous prime is 1198730807. The next prime is 1198730833. The reversal of 1198730821 is 1280378911.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 825700225 + 373030596 = 28735^2 + 19314^2 .

It is a cyclic number.

It is not a de Polignac number, because 1198730821 - 2⁷ = 1198730693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1198730801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 599365410 + 599365411.

It is an arithmetic number, because the mean of its divisors is an integer number (599365411).

Almost surely, 2^1198730821 is an apocalyptic number.

It is an amenable number.

1198730821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1198730821 is an equidigital number, since it uses as much as digits as its factorization.

1198730821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 1198730821 is about 34622.6922841075. The cubic root of 1198730821 is about 1062.2837970423.

The spelling of 1198730821 in words is "one billion, one hundred ninety-eight million, seven hundred thirty thousand, eight hundred twenty-one".