1221684 has 12 divisors (see below), whose sum is σ = 2850624. Its totient is φ = 407224.

The previous prime is 1221667. The next prime is 1221707. The reversal of 1221684 is 4861221.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-3 number, since 3×1221684³ = 5470133342425624512, which contains 333 as substring.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50892 + ... + 50915.

It is an arithmetic number, because the mean of its divisors is an integer number (237552).

2^1221684 is an apocalyptic number.

It is an amenable number.

1221684 is an abundant number, since it is smaller than the sum of its proper divisors (1628940).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221684 is a wasteful number, since it uses less digits than its factorization.

1221684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101814 (or 101812 counting only the distinct ones).

The product of its digits is 768, while the sum is 24.

The square root of 1221684 is about 1105.2981498220. The cubic root of 1221684 is about 106.9021144569.

The spelling of 1221684 in words is "one million, two hundred twenty-one thousand, six hundred eighty-four".