2121809040 has 640 divisors, whose sum is σ = 8574451200. Its totient is φ = 477757440.

The previous prime is 2121809029. The next prime is 2121809051. The reversal of 2121809040 is 409081212.

It is an interprime number because it is at equal distance from previous prime (2121809029) and next prime (2121809051).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 2121808995 and 2121809013.

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, 21874272 + ... + 21874368.

It is an arithmetic number, because the mean of its divisors is an integer number (13397580).

Almost surely, 2^2121809040 is an apocalyptic number.

2121809040 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 2121809040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4287225600).

2121809040 is an abundant number, since it is smaller than the sum of its proper divisors (6452642160).

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

2121809040 is a wasteful number, since it uses less digits than its factorization.

2121809040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192 (or 180 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 2121809040 is about 46063.0984628694. The cubic root of 2121809040 is about 1284.9969547789.

The spelling of 2121809040 in words is "two billion, one hundred twenty-one million, eight hundred nine thousand, forty".