16865643420 has 72 divisors (see below), whose sum is σ = 53053915824. Its totient is φ = 4497503616.

The previous prime is 16865643359. The next prime is 16865643427. The reversal of 16865643420 is 2434656861.

16865643420 is a `hidden beast` number, since 1 + 6 + 86 + 564 + 3 + 4 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16865643427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1730289 + ... + 1740008.

It is an arithmetic number, because the mean of its divisors is an integer number (736859942).

Almost surely, 2^16865643420 is an apocalyptic number.

16865643420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

16865643420 is an abundant number, since it is smaller than the sum of its proper divisors (36188272404).

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

16865643420 is a wasteful number, since it uses less digits than its factorization.

16865643420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3470321 (or 3470307 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 45.

The spelling of 16865643420 in words is "sixteen billion, eight hundred sixty-five million, six hundred forty-three thousand, four hundred twenty".