2145640842 has 24 divisors (see below), whose sum is σ = 4679681760. Its totient is φ = 710476200.

The previous prime is 2145640837. The next prime is 2145640843. The reversal of 2145640842 is 2480465412.

2145640842 is a `hidden beast` number, since 2 + 1 + 4 + 5 + 640 + 8 + 4 + 2 = 666.

It is a super-3 number, since 3×2145640842³ (a number of 29 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2145640797 and 2145640806.

It is not an unprimeable number, because it can be changed into a prime (2145640843) 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 11 ways as a sum of consecutive naturals, for example, 391992 + ... + 397427.

It is an arithmetic number, because the mean of its divisors is an integer number (194986740).

Almost surely, 2^2145640842 is an apocalyptic number.

2145640842 is an abundant number, since it is smaller than the sum of its proper divisors (2534040918).

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

2145640842 is a wasteful number, since it uses less digits than its factorization.

2145640842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 789578 (or 789575 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 36.

The square root of 2145640842 is about 46321.0626173450. The cubic root of 2145640842 is about 1289.7900108888.

The spelling of 2145640842 in words is "two billion, one hundred forty-five million, six hundred forty thousand, eight hundred forty-two".