2120639940 has 120 divisors (see below), whose sum is σ = 6867286272. Its totient is φ = 547248960.

The previous prime is 2120639903. The next prime is 2120640001. The reversal of 2120639940 is 499360212.

2120639940 is a `hidden beast` number, since 2 + 12 + 0 + 639 + 9 + 4 + 0 = 666.

It is a super-2 number, since 2×2120639940² = 8994227510246407200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 2120639895 and 2120639904.

It is an unprimeable number.

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 39 ways as a sum of consecutive naturals, for example, 29107 + ... + 71333.

Almost surely, 2^2120639940 is an apocalyptic number.

2120639940 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 2120639940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3433643136).

2120639940 is an abundant number, since it is smaller than the sum of its proper divisors (4746646332).

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

2120639940 is a wasteful number, since it uses less digits than its factorization.

2120639940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42279 (or 42268 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 2120639940 is about 46050.4065128637. The cubic root of 2120639940 is about 1284.7609036997.

The spelling of 2120639940 in words is "two billion, one hundred twenty million, six hundred thirty-nine thousand, nine hundred forty".