661069656 has 96 divisors (see below), whose sum is σ = 1947123360. Its totient is φ = 201401856.

The previous prime is 661069649. The next prime is 661069663. The reversal of 661069656 is 656960166.

It is an interprime number because it is at equal distance from previous prime (661069649) and next prime (661069663).

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 23 ways as a sum of consecutive naturals, for example, 92980 + ... + 99836.

It is an arithmetic number, because the mean of its divisors is an integer number (20282535).

Almost surely, 2^661069656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661069656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (973561680).

661069656 is an abundant number, since it is smaller than the sum of its proper divisors (1286053704).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661069656 is a wasteful number, since it uses less digits than its factorization.

661069656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6985 (or 6978 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 45.

The square root of 661069656 is about 25711.2748808767. The cubic root of 661069656 is about 871.1288714959.

The spelling of 661069656 in words is "six hundred sixty-one million, sixty-nine thousand, six hundred fifty-six".