2178206940 has 384 divisors, whose sum is σ = 8215216128. Its totient is φ = 418037760.

The previous prime is 2178206939. The next prime is 2178206969. The reversal of 2178206940 is 496028712.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2877042 + ... + 2877798.

It is an arithmetic number, because the mean of its divisors is an integer number (21393792).

Almost surely, 2^2178206940 is an apocalyptic number.

2178206940 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 2178206940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4107608064).

2178206940 is an abundant number, since it is smaller than the sum of its proper divisors (6037009188).

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

2178206940 is a wasteful number, since it uses less digits than its factorization.

2178206940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 837 (or 835 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 2178206940 is about 46671.2646068220. The cubic root of 2178206940 is about 1296.2826624922.

The spelling of 2178206940 in words is "two billion, one hundred seventy-eight million, two hundred six thousand, nine hundred forty".