1521040440 has 64 divisors (see below), whose sum is σ = 4803292800. Its totient is φ = 384262272.

The previous prime is 1521040399. The next prime is 1521040441. The reversal of 1521040440 is 440401251.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1521040441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 331282 + ... + 335841.

It is an arithmetic number, because the mean of its divisors is an integer number (75051450).

Almost surely, 2^1521040440 is an apocalyptic number.

1521040440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1521040440 is an abundant number, since it is smaller than the sum of its proper divisors (3282252360).

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

1521040440 is a wasteful number, since it uses less digits than its factorization.

1521040440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 667156 (or 667152 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 21.

The square root of 1521040440 is about 39000.5184580923. The cubic root of 1521040440 is about 1150.0416972909.

Adding to 1521040440 its reverse (440401251), we get a palindrome (1961441691).

The spelling of 1521040440 in words is "one billion, five hundred twenty-one million, forty thousand, four hundred forty".