1555663140 has 72 divisors (see below), whose sum is σ = 4722157440. Its totient is φ = 414552384.

The previous prime is 1555663117. The next prime is 1555663141. The reversal of 1555663140 is 413665551.

1555663140 is a `hidden beast` number, since 1 + 5 + 556 + 63 + 1 + 40 = 666.

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 = 1555663095 and 1555663104.

It is not an unprimeable number, because it can be changed into a prime (1555663141) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 409771 + ... + 413549.

It is an arithmetic number, because the mean of its divisors is an integer number (65585520).

Almost surely, 2^1555663140 is an apocalyptic number.

1555663140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1555663140 is an abundant number, since it is smaller than the sum of its proper divisors (3166494300).

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

1555663140 is a wasteful number, since it uses less digits than its factorization.

1555663140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6081 (or 6076 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

The square root of 1555663140 is about 39441.8957455141. The cubic root of 1555663140 is about 1158.7022595651.

It can be divided in two parts, 155 and 5663140, that added together give a triangular number (5663295 = T₃₃₆₅).

The spelling of 1555663140 in words is "one billion, five hundred fifty-five million, six hundred sixty-three thousand, one hundred forty".