663555021225 has 24 divisors (see below), whose sum is σ = 1115672178720. Its totient is φ = 347897771520.

The previous prime is 663555021193. The next prime is 663555021247. The reversal of 663555021225 is 522120555366.

It is not a de Polignac number, because 663555021225 - 2⁵ = 663555021193 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74973544 + ... + 74982393.

It is an arithmetic number, because the mean of its divisors is an integer number (46486340780).

Almost surely, 2^663555021225 is an apocalyptic number.

It is an amenable number.

663555021225 is a deficient number, since it is larger than the sum of its proper divisors (452117157495).

663555021225 is a wasteful number, since it uses less digits than its factorization.

663555021225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149956009 (or 149956004 counting only the distinct ones).

The product of its (nonzero) digits is 540000, while the sum is 42.

The spelling of 663555021225 in words is "six hundred sixty-three billion, five hundred fifty-five million, twenty-one thousand, two hundred twenty-five".