661456443 has 16 divisors (see below), whose sum is σ = 928928000. Its totient is φ = 417506400.

The previous prime is 661456409. The next prime is 661456457. The reversal of 661456443 is 344654166.

It is not a de Polignac number, because 661456443 - 2⁹ = 661455931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661456463) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 143133 + ... + 147681.

It is an arithmetic number, because the mean of its divisors is an integer number (58058000).

Almost surely, 2^661456443 is an apocalyptic number.

661456443 is a deficient number, since it is larger than the sum of its proper divisors (267471557).

661456443 is a wasteful number, since it uses less digits than its factorization.

661456443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7122.

The product of its digits is 207360, while the sum is 39.

The square root of 661456443 is about 25718.7955200083. The cubic root of 661456443 is about 871.2987354062.

The spelling of 661456443 in words is "six hundred sixty-one million, four hundred fifty-six thousand, four hundred forty-three".