1198778901 has 4 divisors (see below), whose sum is σ = 1598371872. Its totient is φ = 799185932.

The previous prime is 1198778881. The next prime is 1198778909. The reversal of 1198778901 is 1098778911.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1198778901 - 2⁹ = 1198778389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1198778909) 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 in 3 ways as a sum of consecutive naturals, for example, 199796481 + ... + 199796486.

It is an arithmetic number, because the mean of its divisors is an integer number (399592968).

Almost surely, 2^1198778901 is an apocalyptic number.

It is an amenable number.

1198778901 is a deficient number, since it is larger than the sum of its proper divisors (399592971).

1198778901 is an equidigital number, since it uses as much as digits as its factorization.

1198778901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399592970.

The product of its (nonzero) digits is 254016, while the sum is 51.

The square root of 1198778901 is about 34623.3866194513. The cubic root of 1198778901 is about 1062.2979992639.

It can be divided in two parts, 119877 and 8901, that added together give a triangular number (128778 = T₅₀₇).

The spelling of 1198778901 in words is "one billion, one hundred ninety-eight million, seven hundred seventy-eight thousand, nine hundred one".