1220021 has 8 divisors (see below), whose sum is σ = 1340064.
Its totient is φ = 1101520.
The previous prime is 1219991. The next prime is 1220027. The reversal of 1220021 is 1200221.
It is a sphenic number, since it is the product of 3 distinct primes.
It is a cyclic number.
It is not a de Polignac number, because 1220021 - 26 = 1219957 is a prime.
It is a Curzon number.
It is a junction number, because it is equal to n+sod(n) for n = 1219990 and 1220008.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (1220027) 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, 1886 + ... + 2448.
It is an arithmetic number, because the mean of its divisors is an integer number (167508).
21220021 is an apocalyptic number.
1220021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.
It is an amenable number.
1220021 is a deficient number, since it is larger than the sum of its proper divisors (120043).
1220021 is a wasteful number, since it uses less digits than its factorization.
1220021 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 771.
The product of its (nonzero) digits is 8, while the sum is 8.
The square root of 1220021 is about 1104.5456079312.
The cubic root of 1220021 is about 106.8535861022.
Adding to 1220021 its reverse (1200221), we get a palindrome (2420242).
It can be divided in two parts, 12200 and 21, that added together give a palindrome (12221).
The spelling of 1220021 in words is "one million, two hundred twenty thousand, twenty-one".