661504044 has 12 divisors (see below), whose sum is σ = 1543509464. Its totient is φ = 220501344.

The previous prime is 661504043. The next prime is 661504073. The reversal of 661504044 is 440405166.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (661504043) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27562657 + ... + 27562680.

Almost surely, 2^661504044 is an apocalyptic number.

It is an amenable number.

661504044 is an abundant number, since it is smaller than the sum of its proper divisors (882005420).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661504044 is a wasteful number, since it uses less digits than its factorization.

661504044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55125344 (or 55125342 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 661504044 is about 25719.7209160597. The cubic root of 661504044 is about 871.3196355963.

The spelling of 661504044 in words is "six hundred sixty-one million, five hundred four thousand, forty-four".