1553221004 has 24 divisors (see below), whose sum is σ = 2838544128. Its totient is φ = 742261520.

The previous prime is 1553221003. The next prime is 1553221009. The reversal of 1553221004 is 4001223551.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is not an unprimeable number, because it can be changed into a prime (1553221003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125369 + ... + 137199.

It is an arithmetic number, because the mean of its divisors is an integer number (118272672).

Almost surely, 2^1553221004 is an apocalyptic number.

It is an amenable number.

1553221004 is a deficient number, since it is larger than the sum of its proper divisors (1285323124).

1553221004 is a wasteful number, since it uses less digits than its factorization.

1553221004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13285 (or 13283 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 1553221004 is about 39410.9249320541. The cubic root of 1553221004 is about 1158.0956178384.

Adding to 1553221004 its reverse (4001223551), we get a palindrome (5554444555).

The spelling of 1553221004 in words is "one billion, five hundred fifty-three million, two hundred twenty-one thousand, four".