1216382401 has 6 divisors (see below), whose sum is σ = 1317147990. Its totient is φ = 1122814368.

The previous prime is 1216382399. The next prime is 1216382407. The reversal of 1216382401 is 1042836121.

It can be written as a sum of positive squares in 3 ways, for example, as 142181776 + 1074200625 = 11924^2 + 32775^2 .

It is not a de Polignac number, because 1216382401 - 2¹ = 1216382399 is a prime.

It is a super-2 number, since 2×1216382401² = 2959172290925049602, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1216382401.

It is not an unprimeable number, because it can be changed into a prime (1216382407) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3598596 + ... + 3598933.

It is an arithmetic number, because the mean of its divisors is an integer number (219524665).

Almost surely, 2^1216382401 is an apocalyptic number.

It is an amenable number.

1216382401 is a deficient number, since it is larger than the sum of its proper divisors (100765589).

1216382401 is an equidigital number, since it uses as much as digits as its factorization.

1216382401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7197555 (or 7197542 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 1216382401 is about 34876.6741677013. The cubic root of 1216382401 is about 1067.4725336680.

The spelling of 1216382401 in words is "one billion, two hundred sixteen million, three hundred eighty-two thousand, four hundred one".