21118193040 has 160 divisors (see below), whose sum is σ = 75252254976. Its totient is φ = 4799047680.

The previous prime is 21118193029. The next prime is 21118193051. The reversal of 21118193040 is 4039181112.

It is a Cunningham number, because it is equal to 145321²-1.

It is an interprime number because it is at equal distance from previous prime (21118193029) and next prime (21118193051).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 21118192989 and 21118193007.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 254310 + ... + 326970.

Almost surely, 2^21118193040 is an apocalyptic number.

21118193040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21118193040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37626127488).

21118193040 is an abundant number, since it is smaller than the sum of its proper divisors (54134061936).

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

21118193040 is a wasteful number, since it uses less digits than its factorization.

21118193040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72857 (or 72851 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 30.

The spelling of 21118193040 in words is "twenty-one billion, one hundred eighteen million, one hundred ninety-three thousand, forty".