661019140 has 12 divisors (see below), whose sum is σ = 1388140236. Its totient is φ = 264407648.

The previous prime is 661019131. The next prime is 661019167. The reversal of 661019140 is 41910166.

It can be written as a sum of positive squares in 2 ways, for example, as 90478144 + 570540996 = 9512^2 + 23886^2 .

It is a junction number, because it is equal to n+sod(n) for n = 661019099 and 661019108.

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 in 3 ways as a sum of consecutive naturals, for example, 16525459 + ... + 16525498.

It is an arithmetic number, because the mean of its divisors is an integer number (115678353).

Almost surely, 2^661019140 is an apocalyptic number.

It is an amenable number.

661019140 is an abundant number, since it is smaller than the sum of its proper divisors (727121096).

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

661019140 is a wasteful number, since it uses less digits than its factorization.

661019140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33050966 (or 33050964 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 661019140 is about 25710.2924915295. The cubic root of 661019140 is about 871.1066816673.

The spelling of 661019140 in words is "six hundred sixty-one million, nineteen thousand, one hundred forty".