1216641 has 8 divisors (see below), whose sum is σ = 1628704. Its totient is φ = 807840.

The previous prime is 1216619. The next prime is 1216681. The reversal of 1216641 is 1466121.

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

It is not a de Polignac number, because 1216641 - 2⁶ = 1216577 is a prime.

It is a Duffinian number.

1216641 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1216601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 261 + ... + 1581.

It is an arithmetic number, because the mean of its divisors is an integer number (203588).

2^1216641 is an apocalyptic number.

It is an amenable number.

1216641 is a deficient number, since it is larger than the sum of its proper divisors (412063).

1216641 is a wasteful number, since it uses less digits than its factorization.

1216641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1631.

The product of its digits is 288, while the sum is 21.

The square root of 1216641 is about 1103.0145057976. The cubic root of 1216641 is about 106.7548175388.

It can be divided in two parts, 12 and 16641, that added together give a triangular number (16653 = T₁₈₂).

The spelling of 1216641 in words is "one million, two hundred sixteen thousand, six hundred forty-one".