1198125078921 has 15 divisors (see below), whose sum is σ = 1789806500823. Its totient is φ = 798743485080.

The previous prime is 1198125078911. The next prime is 1198125078949. The reversal of 1198125078921 is 1298705218911.

It is a happy number.

The square root of 1198125078921 is 1094589.

It is a perfect power (a square), and thus also a powerful number.

1198125078921 is a `hidden beast` number, since 11 + 98 + 12 + 507 + 8 + 9 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 222652803321 + 975472275600 = 471861^2 + 987660^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1198125078921 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1198125078911) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 9790491 + ... + 9912111.

Almost surely, 2^{1198125078921} is an apocalyptic number.

1198125078921 is the 1094589-th square number.

1198125078921 is the 547295-th centered octagonal number.

It is an amenable number.

1198125078921 is a deficient number, since it is larger than the sum of its proper divisors (591681421902).

1198125078921 is an frugal number, since it uses more digits than its factorization.

1198125078921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243254 (or 121624 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 54.

The spelling of 1198125078921 in words is "one trillion, one hundred ninety-eight billion, one hundred twenty-five million, seventy-eight thousand, nine hundred twenty-one".