661019836 has 6 divisors (see below), whose sum is σ = 1156784720. Its totient is φ = 330509916.

The previous prime is 661019833. The next prime is 661019873. The reversal of 661019836 is 638910166.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661019831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82627476 + ... + 82627483.

Almost surely, 2^661019836 is an apocalyptic number.

It is an amenable number.

661019836 is a deficient number, since it is larger than the sum of its proper divisors (495764884).

661019836 is a wasteful number, since it uses less digits than its factorization.

661019836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165254963 (or 165254961 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 40.

The square root of 661019836 is about 25710.3060269613. The cubic root of 661019836 is about 871.1069874023.

The spelling of 661019836 in words is "six hundred sixty-one million, nineteen thousand, eight hundred thirty-six".