661123953 has 12 divisors (see below), whose sum is σ = 1091379328. Its totient is φ = 377785080.

The previous prime is 661123927. The next prime is 661124021. The reversal of 661123953 is 359321166.

661123953 is a `hidden beast` number, since 6 + 611 + 2 + 39 + 5 + 3 = 666.

It is not a de Polignac number, because 661123953 - 2¹⁰ = 661122929 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (661133953) 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 11 ways as a sum of consecutive naturals, for example, 5246953 + ... + 5247078.

Almost surely, 2^661123953 is an apocalyptic number.

661123953 is a gapful number since it is divisible by the number (63) formed by its first and last digit.

It is an amenable number.

661123953 is a deficient number, since it is larger than the sum of its proper divisors (430255375).

661123953 is a wasteful number, since it uses less digits than its factorization.

661123953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10494044 (or 10494041 counting only the distinct ones).

The product of its digits is 29160, while the sum is 36.

The square root of 661123953 is about 25712.3307578290. The cubic root of 661123953 is about 871.1527209188.

The spelling of 661123953 in words is "six hundred sixty-one million, one hundred twenty-three thousand, nine hundred fifty-three".