1663661925 has 36 divisors (see below), whose sum is σ = 3024305440. Its totient is φ = 874035360.

The previous prime is 1663661893. The next prime is 1663661927. The reversal of 1663661925 is 5291663661.

1663661925 is a `hidden beast` number, since 1 + 6 + 6 + 3 + 6 + 619 + 25 = 666.

It is not a de Polignac number, because 1663661925 - 2⁵ = 1663661893 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663661927) by changing a digit.

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 35 ways as a sum of consecutive naturals, for example, 40105 + ... + 70254.

Almost surely, 2^1663661925 is an apocalyptic number.

1663661925 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1663661925 is a deficient number, since it is larger than the sum of its proper divisors (1360643515).

1663661925 is a wasteful number, since it uses less digits than its factorization.

1663661925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110442 (or 110434 counting only the distinct ones).

The product of its digits is 349920, while the sum is 45.

The square root of 1663661925 is about 40788.0120255940. The cubic root of 1663661925 is about 1184.9181698554.

The spelling of 1663661925 in words is "one billion, six hundred sixty-three million, six hundred sixty-one thousand, nine hundred twenty-five".