1555004138 has 4 divisors (see below), whose sum is σ = 2332506210. Its totient is φ = 777502068.

The previous prime is 1555004111. The next prime is 1555004147. The reversal of 1555004138 is 8314005551.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1496374489 + 58629649 = 38683^2 + 7657^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 388751033 + ... + 388751036.

Almost surely, 2^1555004138 is an apocalyptic number.

1555004138 is a deficient number, since it is larger than the sum of its proper divisors (777502072).

1555004138 is an equidigital number, since it uses as much as digits as its factorization.

1555004138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 777502071.

The product of its (nonzero) digits is 12000, while the sum is 32.

The square root of 1555004138 is about 39433.5407743205. The cubic root of 1555004138 is about 1158.5386219638.

Adding to 1555004138 its reverse (8314005551), we get a palindrome (9869009689).

The spelling of 1555004138 in words is "one billion, five hundred fifty-five million, four thousand, one hundred thirty-eight".