1225485661 has 4 divisors (see below), whose sum is σ = 1251559872. Its totient is φ = 1199411452.

The previous prime is 1225485641. The next prime is 1225485689. The reversal of 1225485661 is 1665845221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1665845221 = 2381 ⋅699641.

It is a cyclic number.

It is not a de Polignac number, because 1225485661 - 2⁷ = 1225485533 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax 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 (1225485601) 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, 13037035 + ... + 13037128.

It is an arithmetic number, because the mean of its divisors is an integer number (312889968).

Almost surely, 2^1225485661 is an apocalyptic number.

It is an amenable number.

1225485661 is a deficient number, since it is larger than the sum of its proper divisors (26074211).

1225485661 is an equidigital number, since it uses as much as digits as its factorization.

1225485661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26074210.

The product of its digits is 115200, while the sum is 40.

The square root of 1225485661 is about 35006.9373267642. The cubic root of 1225485661 is about 1070.1288635669.

The spelling of 1225485661 in words is "one billion, two hundred twenty-five million, four hundred eighty-five thousand, six hundred sixty-one".