1231352640 has 336 divisors, whose sum is σ = 4895624448. Its totient is φ = 278249472.

The previous prime is 1231352621. The next prime is 1231352699. The reversal of 1231352640 is 462531321.

1231352640 is a `hidden beast` number, since 1 + 2 + 3 + 13 + 5 + 2 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (336).

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 47 ways as a sum of consecutive naturals, for example, 2076184 + ... + 2076776.

Almost surely, 2^1231352640 is an apocalyptic number.

1231352640 is a gapful number since it is divisible by the number (10) 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 1231352640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2447812224).

1231352640 is an abundant number, since it is smaller than the sum of its proper divisors (3664271808).

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

1231352640 is a wasteful number, since it uses less digits than its factorization.

1231352640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 726 (or 713 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 1231352640 is about 35090.6346480083. The cubic root of 1231352640 is about 1071.8338830740.

Adding to 1231352640 its reverse (462531321), we get a palindrome (1693883961).

The spelling of 1231352640 in words is "one billion, two hundred thirty-one million, three hundred fifty-two thousand, six hundred forty".