2139997860 has 768 divisors, whose sum is σ = 9266503680. Its totient is φ = 395642880.

The previous prime is 2139997831. The next prime is 2139997903. The reversal of 2139997860 is 687999312.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 2139997797 and 2139997806.

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 19999927 + ... + 20000033.

It is an arithmetic number, because the mean of its divisors is an integer number (12065760).

Almost surely, 2^2139997860 is an apocalyptic number.

2139997860 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 2139997860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4633251840).

2139997860 is an abundant number, since it is smaller than the sum of its proper divisors (7126505820).

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

2139997860 is a wasteful number, since it uses less digits than its factorization.

2139997860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193 (or 185 counting only the distinct ones).

The product of its (nonzero) digits is 1469664, while the sum is 54.

The square root of 2139997860 is about 46260.1108948087. The cubic root of 2139997860 is about 1288.6583129890.

It can be divided in two parts, 2139 and 997860, that added together give a palindrome (999999).

The spelling of 2139997860 in words is "two billion, one hundred thirty-nine million, nine hundred ninety-seven thousand, eight hundred sixty".