1221120025 has 24 divisors (see below), whose sum is σ = 1663197120. Its totient is φ = 885234240.

The previous prime is 1221120011. The next prime is 1221120029. The reversal of 1221120025 is 5200211221.

It is a happy number.

It is not a de Polignac number, because 1221120025 - 2⁷ = 1221119897 is a prime.

It is a super-2 number, since 2×1221120025² = 2982268230912001250, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221119990 and 1221120008.

It is not an unprimeable number, because it can be changed into a prime (1221120029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 44962 + ... + 66811.

It is an arithmetic number, because the mean of its divisors is an integer number (69299880).

Almost surely, 2^1221120025 is an apocalyptic number.

It is an amenable number.

1221120025 is a deficient number, since it is larger than the sum of its proper divisors (442077095).

1221120025 is a wasteful number, since it uses less digits than its factorization.

1221120025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111825 (or 111820 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 1221120025 is about 34944.5278262563. The cubic root of 1221120025 is about 1068.8566192095.

Adding to 1221120025 its reverse (5200211221), we get a palindrome (6421331246).

The spelling of 1221120025 in words is "one billion, two hundred twenty-one million, one hundred twenty thousand, twenty-five".