1231638648 has 16 divisors (see below), whose sum is σ = 3079096680. Its totient is φ = 410546208.

The previous prime is 1231638607. The next prime is 1231638659. The reversal of 1231638648 is 8468361321.

It is a nude number because it is divisible by every one of its digits.

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 3 ways as a sum of consecutive naturals, for example, 25659115 + ... + 25659162.

Almost surely, 2^1231638648 is an apocalyptic number.

It is an amenable number.

1231638648 is an abundant number, since it is smaller than the sum of its proper divisors (1847458032).

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

1231638648 is a wasteful number, since it uses less digits than its factorization.

1231638648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51318286 (or 51318282 counting only the distinct ones).

The product of its digits is 165888, while the sum is 42.

The square root of 1231638648 is about 35094.7096867890. The cubic root of 1231638648 is about 1071.9168621015.

Adding to 1231638648 its reverse (8468361321), we get a palindrome (9699999969).

The spelling of 1231638648 in words is "one billion, two hundred thirty-one million, six hundred thirty-eight thousand, six hundred forty-eight".