1555656640 has 28 divisors (see below), whose sum is σ = 3704408136. Its totient is φ = 622262528.

The previous prime is 1555656617. The next prime is 1555656659. The reversal of 1555656640 is 466565551.

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 3 ways as a sum of consecutive naturals, for example, 2430394 + ... + 2431033.

Almost surely, 2^1555656640 is an apocalyptic number.

1555656640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1555656640 is an abundant number, since it is smaller than the sum of its proper divisors (2148751496).

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

1555656640 is an equidigital number, since it uses as much as digits as its factorization.

1555656640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4861444 (or 4861434 counting only the distinct ones).

The product of its (nonzero) digits is 540000, while the sum is 43.

The square root of 1555656640 is about 39441.8133457375. The cubic root of 1555656640 is about 1158.7006457677.

The spelling of 1555656640 in words is "one billion, five hundred fifty-five million, six hundred fifty-six thousand, six hundred forty".