1216988401 has 8 divisors (see below), whose sum is σ = 1290759624. Its totient is φ = 1143459840.

The previous prime is 1216988371. The next prime is 1216988407. The reversal of 1216988401 is 1048896121.

It can be written as a sum of positive squares in 4 ways, for example, as 71233600 + 1145754801 = 8440^2 + 33849^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1216988401 - 2⁷ = 1216988273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216988407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50280 + ... + 70441.

It is an arithmetic number, because the mean of its divisors is an integer number (161344953).

Almost surely, 2^1216988401 is an apocalyptic number.

It is an amenable number.

1216988401 is a deficient number, since it is larger than the sum of its proper divisors (73771223).

1216988401 is a wasteful number, since it uses less digits than its factorization.

1216988401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121331.

The product of its (nonzero) digits is 27648, while the sum is 40.

The square root of 1216988401 is about 34885.3608409029. The cubic root of 1216988401 is about 1067.6497753420.

The spelling of 1216988401 in words is "one billion, two hundred sixteen million, nine hundred eighty-eight thousand, four hundred one".