655086978 has 288 divisors, whose sum is σ = 1951971840. Its totient is φ = 156764160.

The previous prime is 655086973. The next prime is 655087001. The reversal of 655086978 is 879680556.

655086978 is a `hidden beast` number, since 6 + 5 + 508 + 69 + 78 = 666.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (655086973) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 6753426 + ... + 6753522.

It is an arithmetic number, because the mean of its divisors is an integer number (6777680).

Almost surely, 2^655086978 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 655086978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (975985920).

655086978 is an abundant number, since it is smaller than the sum of its proper divisors (1296884862).

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

655086978 is a wasteful number, since it uses less digits than its factorization.

655086978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182 (or 172 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 54.

The square root of 655086978 is about 25594.6669835730. Note that the first 3 decimals coincide. The cubic root of 655086978 is about 868.4929995071.

It can be divided in two parts, 6550 and 86978, that added together give a triangular number (93528 = T₄₃₂).

The spelling of 655086978 in words is "six hundred fifty-five million, eighty-six thousand, nine hundred seventy-eight".