21240216198 has 32 divisors (see below), whose sum is σ = 47368487520. Its totient is φ = 7054871040.

The previous prime is 21240216181. The next prime is 21240216199. The reversal of 21240216198 is 89161204212.

21240216198 is a `hidden beast` number, since 2 + 1 + 2 + 402 + 161 + 98 = 666.

It is a super-2 number, since 2×21240216198² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21240216199) 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 15 ways as a sum of consecutive naturals, for example, 684715 + ... + 715062.

It is an arithmetic number, because the mean of its divisors is an integer number (1480265235).

Almost surely, 2^21240216198 is an apocalyptic number.

21240216198 is an abundant number, since it is smaller than the sum of its proper divisors (26128271322).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21240216198 is a wasteful number, since it uses less digits than its factorization.

21240216198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1400069 (or 1400063 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The spelling of 21240216198 in words is "twenty-one billion, two hundred forty million, two hundred sixteen thousand, one hundred ninety-eight".