1221980 has 12 divisors (see below), whose sum is σ = 2566200. Its totient is φ = 488784.

The previous prime is 1221971. The next prime is 1222003. The reversal of 1221980 is 891221.

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, 30530 + ... + 30569.

It is an arithmetic number, because the mean of its divisors is an integer number (213850).

2^1221980 is an apocalyptic number.

1221980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221980 is an abundant number, since it is smaller than the sum of its proper divisors (1344220).

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

1221980 is a wasteful number, since it uses less digits than its factorization.

1221980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61108 (or 61106 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 1221980 is about 1105.4320422351. The cubic root of 1221980 is about 106.9107474778.

The spelling of 1221980 in words is "one million, two hundred twenty-one thousand, nine hundred eighty".