1216603401 has 32 divisors (see below), whose sum is σ = 1852075008. Its totient is φ = 704920320.

The previous prime is 1216603387. The next prime is 1216603411. The reversal of 1216603401 is 1043066121.

It is not a de Polignac number, because 1216603401 - 2¹⁷ = 1216472329 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1216603411) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31135 + ... + 58331.

It is an arithmetic number, because the mean of its divisors is an integer number (57877344).

Almost surely, 2^1216603401 is an apocalyptic number.

It is an amenable number.

1216603401 is a deficient number, since it is larger than the sum of its proper divisors (635471607).

1216603401 is a wasteful number, since it uses less digits than its factorization.

1216603401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27281.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 1216603401 is about 34879.8423304923. The cubic root of 1216603401 is about 1067.5371781263.

Adding to 1216603401 its reverse (1043066121), we get a palindrome (2259669522).

The spelling of 1216603401 in words is "one billion, two hundred sixteen million, six hundred three thousand, four hundred one".