661536288 has 192 divisors, whose sum is σ = 2231712000. Its totient is φ = 186734592.

The previous prime is 661536263. The next prime is 661536307. The reversal of 661536288 is 882635166.

661536288 is a `hidden beast` number, since 6 + 6 + 15 + 3 + 628 + 8 = 666.

661536288 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 537658 + ... + 538886.

It is an arithmetic number, because the mean of its divisors is an integer number (11623500).

Almost surely, 2^661536288 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 661536288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1115856000).

661536288 is an abundant number, since it is smaller than the sum of its proper divisors (1570175712).

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

661536288 is a wasteful number, since it uses less digits than its factorization.

661536288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1344 (or 1330 counting only the distinct ones).

The product of its digits is 414720, while the sum is 45.

The square root of 661536288 is about 25720.3477425948. The cubic root of 661536288 is about 871.3337924127. Note that the first 3 decimals are identical.

The spelling of 661536288 in words is "six hundred sixty-one million, five hundred thirty-six thousand, two hundred eighty-eight".