20198724081 has 4 divisors (see below), whose sum is σ = 26931632112. Its totient is φ = 13465816052.

The previous prime is 20198724061. The next prime is 20198724101. The reversal of 20198724081 is 18042789102.

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 an interprime number because it is at equal distance from previous prime (20198724061) and next prime (20198724101).

It is a cyclic number.

It is not a de Polignac number, because 20198724081 - 2²⁵ = 20165169649 is a prime.

It is a super-2 number, since 2×20198724081² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20198724061) 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, 3366454011 + ... + 3366454016.

It is an arithmetic number, because the mean of its divisors is an integer number (6732908028).

Almost surely, 2^20198724081 is an apocalyptic number.

It is an amenable number.

20198724081 is a deficient number, since it is larger than the sum of its proper divisors (6732908031).

20198724081 is an equidigital number, since it uses as much as digits as its factorization.

20198724081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6732908030.

The product of its (nonzero) digits is 64512, while the sum is 42.

The spelling of 20198724081 in words is "twenty billion, one hundred ninety-eight million, seven hundred twenty-four thousand, eighty-one".