661630436 has 24 divisors (see below), whose sum is σ = 1172519040. Its totient is φ = 326646432.

The previous prime is 661630423. The next prime is 661630439. The reversal of 661630436 is 634036166.

It is a junction number, because it is equal to n+sod(n) for n = 661630396 and 661630405.

It is not an unprimeable number, because it can be changed into a prime (661630439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 131381 + ... + 136323.

It is an arithmetic number, because the mean of its divisors is an integer number (48854960).

Almost surely, 2^661630436 is an apocalyptic number.

It is an amenable number.

661630436 is a deficient number, since it is larger than the sum of its proper divisors (510888604).

661630436 is a wasteful number, since it uses less digits than its factorization.

661630436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5363 (or 5361 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 35.

The square root of 661630436 is about 25722.1779015697. The cubic root of 661630436 is about 871.3751257172.

The spelling of 661630436 in words is "six hundred sixty-one million, six hundred thirty thousand, four hundred thirty-six".