1555666240 has 56 divisors (see below), whose sum is σ = 3709126440. Its totient is φ = 621477888.

The previous prime is 1555666223. The next prime is 1555666247. The reversal of 1555666240 is 426665551.

It can be written as a sum of positive squares in 4 ways, for example, as 131056704 + 1424609536 = 11448^2 + 37744^2 .

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 1555666193 and 1555666202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1555666247) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 294664 + ... + 299896.

Almost surely, 2^1555666240 is an apocalyptic number.

1555666240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1555666240 is an abundant number, since it is smaller than the sum of its proper divisors (2153460200).

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

1555666240 is an equidigital number, since it uses as much as digits as its factorization.

1555666240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6179 (or 6169 counting only the distinct ones).

The product of its (nonzero) digits is 216000, while the sum is 40.

The square root of 1555666240 is about 39441.9350438084. The cubic root of 1555666240 is about 1158.7030292207.

It can be divided in two parts, 15556 and 66240, that added together give a square (81796 = 286²).

The spelling of 1555666240 in words is "one billion, five hundred fifty-five million, six hundred sixty-six thousand, two hundred forty".