1540640556 has 324 divisors, whose sum is σ = 5140192512. Its totient is φ = 385596288.

The previous prime is 1540640539. The next prime is 1540640581. The reversal of 1540640556 is 6550460451.

1540640556 is a `hidden beast` number, since 1 + 5 + 4 + 0 + 640 + 5 + 5 + 6 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 1540640556.

It is a congruent number.

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 107 ways as a sum of consecutive naturals, for example, 12130965 + ... + 12131091.

Almost surely, 2^1540640556 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1540640556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2570096256).

1540640556 is an abundant number, since it is smaller than the sum of its proper divisors (3599551956).

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

1540640556 is a wasteful number, since it uses less digits than its factorization.

1540640556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210 (or 175 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

The square root of 1540640556 is about 39250.9943313542. The cubic root of 1540640556 is about 1154.9604394164.

The spelling of 1540640556 in words is "one billion, five hundred forty million, six hundred forty thousand, five hundred fifty-six".