1555404040 has 32 divisors (see below), whose sum is σ = 3534318360. Its totient is φ = 616000000.

The previous prime is 1555404007. The next prime is 1555404043. The reversal of 1555404040 is 404045551.

It can be written as a sum of positive squares in 4 ways, for example, as 1548737316 + 6666724 = 39354^2 + 2582^2 .

It is not an unprimeable number, because it can be changed into a prime (1555404043) 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, 188461 + ... + 196540.

Almost surely, 2^1555404040 is an apocalyptic number.

1555404040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1555404040 is an abundant number, since it is smaller than the sum of its proper divisors (1978914320).

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

1555404040 is a wasteful number, since it uses less digits than its factorization.

1555404040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 385113 (or 385109 counting only the distinct ones).

The product of its (nonzero) digits is 8000, while the sum is 28.

The square root of 1555404040 is about 39438.6110303089. The cubic root of 1555404040 is about 1158.6379276377.

Adding to 1555404040 its reverse (404045551), we get a palindrome (1959449591).

The spelling of 1555404040 in words is "one billion, five hundred fifty-five million, four hundred four thousand, forty".