21155363198 has 4 divisors (see below), whose sum is σ = 31733044800. Its totient is φ = 10577681598.

The previous prime is 21155363189. The next prime is 21155363231. The reversal of 21155363198 is 89136355112.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5288840798 + ... + 5288840801.

It is an arithmetic number, because the mean of its divisors is an integer number (7933261200).

Almost surely, 2^21155363198 is an apocalyptic number.

21155363198 is a deficient number, since it is larger than the sum of its proper divisors (10577681602).

21155363198 is a wasteful number, since it uses less digits than its factorization.

21155363198 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10577681601.

The product of its digits is 194400, while the sum is 44.

The spelling of 21155363198 in words is "twenty-one billion, one hundred fifty-five million, three hundred sixty-three thousand, one hundred ninety-eight".