1220555137 has 4 divisors (see below), whose sum is σ = 1292352516. Its totient is φ = 1148757760.

The previous prime is 1220555113. The next prime is 1220555207. The reversal of 1220555137 is 7315550221.

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 798006001 + 422549136 = 28249^2 + 20556^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220555137 - 2⁷ = 1220555009 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220555099 and 1220555108.

It is not an unprimeable number, because it can be changed into a prime (1220555437) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35898664 + ... + 35898697.

It is an arithmetic number, because the mean of its divisors is an integer number (323088129).

Almost surely, 2^1220555137 is an apocalyptic number.

1220555137 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

1220555137 is a deficient number, since it is larger than the sum of its proper divisors (71797379).

1220555137 is an equidigital number, since it uses as much as digits as its factorization.

1220555137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71797378.

The product of its (nonzero) digits is 10500, while the sum is 31.

The square root of 1220555137 is about 34936.4442523849. Note that the first 3 decimals coincide. The cubic root of 1220555137 is about 1068.6917767171.

The spelling of 1220555137 in words is "one billion, two hundred twenty million, five hundred fifty-five thousand, one hundred thirty-seven".