1220165225 has 36 divisors (see below), whose sum is σ = 1615643988. Its totient is φ = 913920000.

The previous prime is 1220165209. The next prime is 1220165257. The reversal of 1220165225 is 5225610221.

It can be written as a sum of positive squares in 18 ways, for example, as 147209689 + 1072955536 = 12133^2 + 32756^2 .

It is not a de Polignac number, because 1220165225 - 2⁴ = 1220165209 is a prime.

It is a super-3 number, since 3×1220165225³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220165194 and 1220165203.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2029925 + ... + 2030525.

Almost surely, 2^1220165225 is an apocalyptic number.

It is an amenable number.

1220165225 is a deficient number, since it is larger than the sum of its proper divisors (395478763).

1220165225 is a wasteful number, since it uses less digits than its factorization.

1220165225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 926 (or 904 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 1220165225 is about 34930.8635020665. The cubic root of 1220165225 is about 1068.5779650820.

Adding to 1220165225 its reverse (5225610221), we get a palindrome (6445775446).

The spelling of 1220165225 in words is "one billion, two hundred twenty million, one hundred sixty-five thousand, two hundred twenty-five".