1004121638 has 24 divisors (see below), whose sum is σ = 1660721328. Its totient is φ = 452641392.

The previous prime is 1004121637. The next prime is 1004121641. The reversal of 1004121638 is 8361214001.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1004121631) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37631 + ... + 58517.

It is an arithmetic number, because the mean of its divisors is an integer number (69196722).

Almost surely, 2^1004121638 is an apocalyptic number.

1004121638 is a deficient number, since it is larger than the sum of its proper divisors (656599690).

1004121638 is a wasteful number, since it uses less digits than its factorization.

1004121638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20988 (or 20945 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 1004121638 is about 31687.8784079970. The cubic root of 1004121638 is about 1001.3719960992.

Adding to 1004121638 its reverse (8361214001), we get a palindrome (9365335639).

The spelling of 1004121638 in words is "one billion, four million, one hundred twenty-one thousand, six hundred thirty-eight".