661263376 has 10 divisors (see below), whose sum is σ = 1281197822. Its totient is φ = 330631680.

The previous prime is 661263373. The next prime is 661263389. The reversal of 661263376 is 673362166.

It can be written as a sum of positive squares in only one way, i.e., 618019600 + 43243776 = 24860^2 + 6576^2 .

It is not an unprimeable number, because it can be changed into a prime (661263373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20664465 + ... + 20664496.

Almost surely, 2^661263376 is an apocalyptic number.

It is an amenable number.

661263376 is a deficient number, since it is larger than the sum of its proper divisors (619934446).

661263376 is a wasteful number, since it uses less digits than its factorization.

661263376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41328969 (or 41328963 counting only the distinct ones).

The product of its digits is 163296, while the sum is 40.

The square root of 661263376 is about 25715.0418238042. The cubic root of 661263376 is about 871.2139551186.

The spelling of 661263376 in words is "six hundred sixty-one million, two hundred sixty-three thousand, three hundred seventy-six".