1216400115 has 16 divisors (see below), whose sum is σ = 2224274688. Its totient is φ = 556068576.

The previous prime is 1216400093. The next prime is 1216400179. The reversal of 1216400115 is 5110046121.

It is not a de Polignac number, because 1216400115 - 2¹⁴ = 1216383731 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 1216400091 and 1216400100.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 5792277 + ... + 5792486.

It is an arithmetic number, because the mean of its divisors is an integer number (139017168).

Almost surely, 2^1216400115 is an apocalyptic number.

1216400115 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1216400115 is a deficient number, since it is larger than the sum of its proper divisors (1007874573).

1216400115 is a wasteful number, since it uses less digits than its factorization.

1216400115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11584778.

The product of its (nonzero) digits is 240, while the sum is 21.

The square root of 1216400115 is about 34876.9281187435. The cubic root of 1216400115 is about 1067.4777154586.

Adding to 1216400115 its reverse (5110046121), we get a palindrome (6326446236).

The spelling of 1216400115 in words is "one billion, two hundred sixteen million, four hundred thousand, one hundred fifteen".