661129964 has 36 divisors (see below), whose sum is σ = 1274300664. Its totient is φ = 299904000.

The previous prime is 661129951. The next prime is 661129969. The reversal of 661129964 is 469921166.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is not an unprimeable number, because it can be changed into a prime (661129969) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 309179 + ... + 311309.

Almost surely, 2^661129964 is an apocalyptic number.

It is an amenable number.

661129964 is a deficient number, since it is larger than the sum of its proper divisors (613170700).

661129964 is a wasteful number, since it uses less digits than its factorization.

661129964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2798 (or 2785 counting only the distinct ones).

The product of its digits is 139968, while the sum is 44.

The square root of 661129964 is about 25712.4476470055. The cubic root of 661129964 is about 871.1553611111.

The spelling of 661129964 in words is "six hundred sixty-one million, one hundred twenty-nine thousand, nine hundred sixty-four".