1131211728 has 30 divisors (see below), whose sum is σ = 3165822114. Its totient is φ = 377070528.

The previous prime is 1131211727. The next prime is 1131211747. The reversal of 1131211728 is 8271121311.

It can be written as a sum of positive squares in only one way, i.e., 680583744 + 450627984 = 26088^2 + 21228^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1131211727) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3927675 + ... + 3927962.

Almost surely, 2^1131211728 is an apocalyptic number.

1131211728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1131211728 is an abundant number, since it is smaller than the sum of its proper divisors (2034610386).

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

1131211728 is a wasteful number, since it uses less digits than its factorization.

1131211728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7855651 (or 7855642 counting only the distinct ones).

The product of its digits is 672, while the sum is 27.

The square root of 1131211728 is about 33633.4911658008. The cubic root of 1131211728 is about 1041.9526087865.

The spelling of 1131211728 in words is "one billion, one hundred thirty-one million, two hundred eleven thousand, seven hundred twenty-eight".