1198172621 has 2 divisors, whose sum is σ = 1198172622. Its totient is φ = 1198172620.

The previous prime is 1198172617. The next prime is 1198172663. The reversal of 1198172621 is 1262718911.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1173062500 + 25110121 = 34250^2 + 5011^2 .

It is a cyclic number.

It is not a de Polignac number, because 1198172621 - 2² = 1198172617 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1198172611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 599086310 + 599086311.

It is an arithmetic number, because the mean of its divisors is an integer number (599086311).

Almost surely, 2^1198172621 is an apocalyptic number.

It is an amenable number.

1198172621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1198172621 is an equidigital number, since it uses as much as digits as its factorization.

1198172621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 38.

The square root of 1198172621 is about 34614.6301583593. The cubic root of 1198172621 is about 1062.1188840446.

The spelling of 1198172621 in words is "one billion, one hundred ninety-eight million, one hundred seventy-two thousand, six hundred twenty-one".