1221516 has 18 divisors (see below), whose sum is σ = 3087812. Its totient is φ = 407160.

The previous prime is 1221503. The next prime is 1221523. The reversal of 1221516 is 6151221.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16930 + ... + 17001.

2^1221516 is an apocalyptic number.

It is an amenable number.

1221516 is an abundant number, since it is smaller than the sum of its proper divisors (1866296).

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

1221516 is a wasteful number, since it uses less digits than its factorization.

1221516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33941 (or 33936 counting only the distinct ones).

The product of its digits is 120, while the sum is 18.

The square root of 1221516 is about 1105.2221496152. Note that the first 3 decimals coincide. The cubic root of 1221516 is about 106.8972140139.

Adding to 1221516 its reverse (6151221), we get a palindrome (7372737).

It can be divided in two parts, 1221 and 516, that multiplied together give a palindrome (630036).

The spelling of 1221516 in words is "one million, two hundred twenty-one thousand, five hundred sixteen".