1531404 has 72 divisors (see below), whose sum is σ = 4542720. Its totient is φ = 425952.

The previous prime is 1531379. The next prime is 1531447. The reversal of 1531404 is 4041351.

It is a happy number.

It is a super-2 number, since 2×1531404² = 4690396422432, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14817 + ... + 14919.

2^1531404 is an apocalyptic number.

1531404 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 1531404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2271360).

1531404 is an abundant number, since it is smaller than the sum of its proper divisors (3011316).

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

1531404 is a wasteful number, since it uses less digits than its factorization.

1531404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179 (or 174 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 1531404 is about 1237.4990909088. The cubic root of 1531404 is about 115.2647711566.

1531404 divided by its sum of digits (18) gives a triangular number (85078 = T₄₁₂).

Adding to 1531404 its reverse (4041351), we get a palindrome (5572755).

The spelling of 1531404 in words is "one million, five hundred thirty-one thousand, four hundred four".