661377652 has 12 divisors (see below), whose sum is σ = 1246442596. Its totient is φ = 305251200.

The previous prime is 661377643. The next prime is 661377679. The reversal of 661377652 is 256773166.

It can be written as a sum of positive squares in 2 ways, for example, as 34175716 + 627201936 = 5846^2 + 25044^2 .

It is a junction number, because it is equal to n+sod(n) for n = 661377599 and 661377608.

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 6359349 + ... + 6359452.

Almost surely, 2^661377652 is an apocalyptic number.

It is an amenable number.

661377652 is a deficient number, since it is larger than the sum of its proper divisors (585064944).

661377652 is a wasteful number, since it uses less digits than its factorization.

661377652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12718818 (or 12718816 counting only the distinct ones).

The product of its digits is 317520, while the sum is 43.

The square root of 661377652 is about 25717.2636958134. The cubic root of 661377652 is about 871.2641384067.

The spelling of 661377652 in words is "six hundred sixty-one million, three hundred seventy-seven thousand, six hundred fifty-two".