21111794840 has 32 divisors (see below), whose sum is σ = 49033848960. Its totient is φ = 8172307200.

The previous prime is 21111794807. The next prime is 21111794849. The reversal of 21111794840 is 4849711112.

It is a junction number, because it is equal to n+sod(n) for n = 21111794794 and 21111794803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111794849) 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 7 ways as a sum of consecutive naturals, for example, 8511581 + ... + 8514060.

It is an arithmetic number, because the mean of its divisors is an integer number (1532307780).

Almost surely, 2^21111794840 is an apocalyptic number.

21111794840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21111794840 is an abundant number, since it is smaller than the sum of its proper divisors (27922054120).

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

21111794840 is a wasteful number, since it uses less digits than its factorization.

21111794840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17025683 (or 17025679 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 38.

The spelling of 21111794840 in words is "twenty-one billion, one hundred eleven million, seven hundred ninety-four thousand, eight hundred forty".