1216728746 has 4 divisors (see below), whose sum is σ = 1825093122. Its totient is φ = 608364372.

The previous prime is 1216728713. The next prime is 1216728787. The reversal of 1216728746 is 6478276121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6478276121 = 353 ⋅18352057.

It can be written as a sum of positive squares in only one way, i.e., 1211388025 + 5340721 = 34805^2 + 2311^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1216728697 and 1216728706.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 304182185 + ... + 304182188.

Almost surely, 2^1216728746 is an apocalyptic number.

1216728746 is a deficient number, since it is larger than the sum of its proper divisors (608364376).

1216728746 is an equidigital number, since it uses as much as digits as its factorization.

1216728746 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 608364375.

The product of its digits is 225792, while the sum is 44.

The square root of 1216728746 is about 34881.6390956618. The cubic root of 1216728746 is about 1067.5738391702.

The spelling of 1216728746 in words is "one billion, two hundred sixteen million, seven hundred twenty-eight thousand, seven hundred forty-six".