198987653 has 4 divisors (see below), whose sum is σ = 201790368. Its totient is φ = 196184940.

The previous prime is 198987623. The next prime is 198987661. The reversal of 198987653 is 356789891.

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, and also an emirpimes, since its reverse is a distinct semiprime: 356789891 = 17683 ⋅20177.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198987653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198987623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1401251 + ... + 1401392.

It is an arithmetic number, because the mean of its divisors is an integer number (50447592).

Almost surely, 2^198987653 is an apocalyptic number.

It is an amenable number.

198987653 is a deficient number, since it is larger than the sum of its proper divisors (2802715).

198987653 is an equidigital number, since it uses as much as digits as its factorization.

198987653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2802714.

The product of its digits is 3265920, while the sum is 56.

The square root of 198987653 is about 14106.2983450656. The cubic root of 198987653 is about 583.8151712672.

The spelling of 198987653 in words is "one hundred ninety-eight million, nine hundred eighty-seven thousand, six hundred fifty-three".