661037648 has 10 divisors (see below), whose sum is σ = 1280760474. Its totient is φ = 330518816.

The previous prime is 661037633. The next prime is 661037681. The reversal of 661037648 is 846730166.

It can be written as a sum of positive squares in only one way, i.e., 533979664 + 127057984 = 23108^2 + 11272^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20657411 + ... + 20657442.

Almost surely, 2^661037648 is an apocalyptic number.

It is an amenable number.

661037648 is a deficient number, since it is larger than the sum of its proper divisors (619722826).

661037648 is a wasteful number, since it uses less digits than its factorization.

661037648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41314861 (or 41314855 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 41.

The square root of 661037648 is about 25710.6524226827. The cubic root of 661037648 is about 871.1148116850.

The spelling of 661037648 in words is "six hundred sixty-one million, thirty-seven thousand, six hundred forty-eight".