1663890425 has 6 divisors (see below), whose sum is σ = 2063224158. Its totient is φ = 1331112320.

The previous prime is 1663890421. The next prime is 1663890443. The reversal of 1663890425 is 5240983661.

It can be written as a sum of positive squares in 3 ways, for example, as 64770304 + 1599120121 = 8048^2 + 39989^2 .

It is not a de Polignac number, because 1663890425 - 2² = 1663890421 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1663890421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 33277784 + ... + 33277833.

It is an arithmetic number, because the mean of its divisors is an integer number (343870693).

Almost surely, 2^1663890425 is an apocalyptic number.

It is an amenable number.

1663890425 is a deficient number, since it is larger than the sum of its proper divisors (399333733).

1663890425 is an equidigital number, since it uses as much as digits as its factorization.

1663890425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66555627 (or 66555622 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 44.

The square root of 1663890425 is about 40790.8129975366. The cubic root of 1663890425 is about 1184.9724159341.

The spelling of 1663890425 in words is "one billion, six hundred sixty-three million, eight hundred ninety thousand, four hundred twenty-five".