2540906640 has 60 divisors (see below), whose sum is σ = 8533213884. Its totient is φ = 677574912.

The previous prime is 2540906629. The next prime is 2540906647. The reversal of 2540906640 is 466090452.

2540906640 is a `hidden beast` number, since 2 + 5 + 4 + 0 + 9 + 0 + 6 + 640 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1883907216 + 656999424 = 43404^2 + 25632^2 .

It is a tau number, because it is divible by the number of its divisors (60).

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 = 2540906595 and 2540906604.

It is not an unprimeable number, because it can be changed into a prime (2540906647) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1763799 + ... + 1765238.

Almost surely, 2^2540906640 is an apocalyptic number.

2540906640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2540906640 is an abundant number, since it is smaller than the sum of its proper divisors (5992307244).

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

2540906640 is a wasteful number, since it uses less digits than its factorization.

2540906640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3529056 (or 3529047 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 2540906640 is about 50407.4065986339. The cubic root of 2540906640 is about 1364.5713100529.

The spelling of 2540906640 in words is "two billion, five hundred forty million, nine hundred six thousand, six hundred forty".