1216815 has 16 divisors (see below), whose sum is σ = 2032128. Its totient is φ = 620576.

The previous prime is 1216807. The next prime is 1216823. The reversal of 1216815 is 5186121.

It is an interprime number because it is at equal distance from previous prime (1216807) and next prime (1216823).

It is a cyclic number.

It is not a de Polignac number, because 1216815 - 2³ = 1216807 is a prime.

1216815 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1419 + ... + 2108.

It is an arithmetic number, because the mean of its divisors is an integer number (127008).

2^1216815 is an apocalyptic number.

1216815 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1216815 is a deficient number, since it is larger than the sum of its proper divisors (815313).

1216815 is a wasteful number, since it uses less digits than its factorization.

1216815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3558.

The product of its digits is 480, while the sum is 24.

The square root of 1216815 is about 1103.0933777337. The cubic root of 1216815 is about 106.7599065373.

The spelling of 1216815 in words is "one million, two hundred sixteen thousand, eight hundred fifteen".