1231688728 has 16 divisors (see below), whose sum is σ = 2309792760. Its totient is φ = 615744000.

The previous prime is 1231688713. The next prime is 1231688761. The reversal of 1231688728 is 8278861321.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 78328 + ... + 92728.

Almost surely, 2^1231688728 is an apocalyptic number.

It is an amenable number.

1231688728 is a deficient number, since it is larger than the sum of its proper divisors (1078104032).

1231688728 is a wasteful number, since it uses less digits than its factorization.

1231688728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25098 (or 25094 counting only the distinct ones).

The product of its digits is 258048, while the sum is 46.

The square root of 1231688728 is about 35095.4231773888. The cubic root of 1231688728 is about 1071.9313904074.

The spelling of 1231688728 in words is "one billion, two hundred thirty-one million, six hundred eighty-eight thousand, seven hundred twenty-eight".