1272731728 has 10 divisors (see below), whose sum is σ = 2465917754. Its totient is φ = 636365856.

The previous prime is 1272731689. The next prime is 1272731731. The reversal of 1272731728 is 8271372721.

It can be written as a sum of positive squares in only one way, i.e., 909143104 + 363588624 = 30152^2 + 19068^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39772851 + ... + 39772882.

Almost surely, 2^1272731728 is an apocalyptic number.

It is an amenable number.

1272731728 is a deficient number, since it is larger than the sum of its proper divisors (1193186026).

1272731728 is an equidigital number, since it uses as much as digits as its factorization.

1272731728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79545741 (or 79545735 counting only the distinct ones).

The product of its digits is 65856, while the sum is 40.

The square root of 1272731728 is about 35675.3658425530. The cubic root of 1272731728 is about 1083.7080271913.

The spelling of 1272731728 in words is "one billion, two hundred seventy-two million, seven hundred thirty-one thousand, seven hundred twenty-eight".