1220557 has 4 divisors (see below), whose sum is σ = 1314460. Its totient is φ = 1126656.

The previous prime is 1220507. The next prime is 1220591. The reversal of 1220557 is 7550221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 67081 + 1153476 = 259^2 + 1074^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1220557 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46932 + ... + 46957.

It is an arithmetic number, because the mean of its divisors is an integer number (328615).

2^1220557 is an apocalyptic number.

It is an amenable number.

1220557 is a deficient number, since it is larger than the sum of its proper divisors (93903).

1220557 is an equidigital number, since it uses as much as digits as its factorization.

1220557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93902.

The product of its (nonzero) digits is 700, while the sum is 22.

The square root of 1220557 is about 1104.7882149987. The cubic root of 1220557 is about 106.8692320451.

Adding to 1220557 its reverse (7550221), we get a palindrome (8770778).

The spelling of 1220557 in words is "one million, two hundred twenty thousand, five hundred fifty-seven".