1220145525 has 42 divisors (see below), whose sum is σ = 2268466850. Its totient is φ = 650734560.

The previous prime is 1220145517. The next prime is 1220145541. The reversal of 1220145525 is 5255410221.

1220145525 is a `hidden beast` number, since 1 + 2 + 201 + 455 + 2 + 5 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 308950929 + 911194596 = 17577^2 + 30186^2 .

It is not a de Polignac number, because 1220145525 - 2³ = 1220145517 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 41 ways as a sum of consecutive naturals, for example, 15250 + ... + 51699.

Almost surely, 2^1220145525 is an apocalyptic number.

1220145525 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1220145525 is a deficient number, since it is larger than the sum of its proper divisors (1048321325).

1220145525 is an frugal number, since it uses more digits than its factorization.

1220145525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66977 (or 66957 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 27.

The square root of 1220145525 is about 34930.5815153427. The cubic root of 1220145525 is about 1068.5722141944.

Adding to 1220145525 its reverse (5255410221), we get a palindrome (6475555746).

The spelling of 1220145525 in words is "one billion, two hundred twenty million, one hundred forty-five thousand, five hundred twenty-five".