1216512428 has 12 divisors (see below), whose sum is σ = 2129142960. Its totient is φ = 608185872.

The previous prime is 1216512397. The next prime is 1216512433. The reversal of 1216512428 is 8242156121.

It is a junction number, because it is equal to n+sod(n) for n = 1216512394 and 1216512403.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51350 + ... + 71202.

It is an arithmetic number, because the mean of its divisors is an integer number (177428580).

Almost surely, 2^1216512428 is an apocalyptic number.

It is an amenable number.

1216512428 is a deficient number, since it is larger than the sum of its proper divisors (912630532).

1216512428 is a wasteful number, since it uses less digits than its factorization.

1216512428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35176 (or 35174 counting only the distinct ones).

The product of its digits is 7680, while the sum is 32.

The square root of 1216512428 is about 34878.5382147819. The cubic root of 1216512428 is about 1067.5105686657.

Adding to 1216512428 its reverse (8242156121), we get a palindrome (9458668549).

The spelling of 1216512428 in words is "one billion, two hundred sixteen million, five hundred twelve thousand, four hundred twenty-eight".