1521604 has 24 divisors (see below), whose sum is σ = 3143168. Its totient is φ = 630720.

The previous prime is 1521599. The next prime is 1521613. The reversal of 1521604 is 4061251.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9 + ... + 1744.

2^1521604 is an apocalyptic number.

1521604 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1521604, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1571584).

1521604 is an abundant number, since it is smaller than the sum of its proper divisors (1621564).

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

1521604 is a wasteful number, since it uses less digits than its factorization.

1521604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1795 (or 1793 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 1521604 is about 1233.5331369688. The cubic root of 1521604 is about 115.0183713561.

Adding to 1521604 its reverse (4061251), we get a palindrome (5582855).

The spelling of 1521604 in words is "one million, five hundred twenty-one thousand, six hundred four".