1531331640 has 48 divisors (see below), whose sum is σ = 4976829000. Its totient is φ = 408355008.

The previous prime is 1531331587. The next prime is 1531331671. The reversal of 1531331640 is 461331351.

1531331640 is a `hidden beast` number, since 1 + 5 + 3 + 13 + 3 + 1 + 640 = 666.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 2126490 + ... + 2127209.

Almost surely, 2^1531331640 is an apocalyptic number.

1531331640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1531331640 is an abundant number, since it is smaller than the sum of its proper divisors (3445497360).

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

1531331640 is a wasteful number, since it uses less digits than its factorization.

1531331640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4253716 (or 4253709 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 1531331640 is about 39132.2327499978. The cubic root of 1531331640 is about 1152.6295567877.

Adding to 1531331640 its reverse (461331351), we get a palindrome (1992662991).

The spelling of 1531331640 in words is "one billion, five hundred thirty-one million, three hundred thirty-one thousand, six hundred forty".