278578657520640 has 1760 divisors, whose sum is σ = 1044327651840000. Its totient is φ = 71216578363392.

The previous prime is 278578657520617. The next prime is 278578657520651. The reversal of 278578657520640 is 46025756875872.

It is a happy number.

278578657520640 is a `hidden beast` number, since 2 + 7 + 8 + 5 + 7 + 8 + 6 + 57 + 520 + 6 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 581583835921 + ... + 581583836399.

It is an arithmetic number, because the mean of its divisors is an integer number (593367984000).

Almost surely, 2^{278578657520640} is an apocalyptic number.

278578657520640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 278578657520640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (522163825920000).

278578657520640 is an abundant number, since it is smaller than the sum of its proper divisors (765748994319360).

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

278578657520640 is an frugal number, since it uses more digits than its factorization.

278578657520640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 759 (or 717 counting only the distinct ones).

The product of its (nonzero) digits is 1580544000, while the sum is 72.

The spelling of 278578657520640 in words is "two hundred seventy-eight trillion, five hundred seventy-eight billion, six hundred fifty-seven million, five hundred twenty thousand, six hundred forty".