198521651 has 2 divisors, whose sum is σ = 198521652. Its totient is φ = 198521650.

The previous prime is 198521629. The next prime is 198521657. The reversal of 198521651 is 156125891.

It is a strong prime.

It is an emirp because it is prime and its reverse (156125891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 198521651 - 2¹⁸ = 198259507 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (198521657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99260825 + 99260826.

It is an arithmetic number, because the mean of its divisors is an integer number (99260826).

Almost surely, 2^198521651 is an apocalyptic number.

198521651 is a deficient number, since it is larger than the sum of its proper divisors (1).

198521651 is an equidigital number, since it uses as much as digits as its factorization.

198521651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21600, while the sum is 38.

The square root of 198521651 is about 14089.7711478931. The cubic root of 198521651 is about 583.3590764875.

The spelling of 198521651 in words is "one hundred ninety-eight million, five hundred twenty-one thousand, six hundred fifty-one".