1216034521 has 16 divisors (see below), whose sum is σ = 1321051536. Its totient is φ = 1112702976.

The previous prime is 1216034441. The next prime is 1216034579. The reversal of 1216034521 is 1254306121.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 1860496 + 1214174025 = 1364^2 + 34845^2 .

It is a cyclic number.

It is not a de Polignac number, because 1216034521 - 2⁹ = 1216034009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216034581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 884991 + ... + 886363.

It is an arithmetic number, because the mean of its divisors is an integer number (82565721).

Almost surely, 2^1216034521 is an apocalyptic number.

It is an amenable number.

1216034521 is a deficient number, since it is larger than the sum of its proper divisors (105017015).

1216034521 is a wasteful number, since it uses less digits than its factorization.

1216034521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1932.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 1216034521 is about 34871.6865235968. The cubic root of 1216034521 is about 1067.3707598201.

The spelling of 1216034521 in words is "one billion, two hundred sixteen million, thirty-four thousand, five hundred twenty-one".