661004838585 has 144 divisors (see below), whose sum is σ = 1439930039184. Its totient is φ = 278034591744.

The previous prime is 661004838583. The next prime is 661004838587. The reversal of 661004838585 is 585838400166.

661004838585 is a `hidden beast` number, since 6 + 6 + 1 + 0 + 0 + 483 + 85 + 85 = 666.

It is an interprime number because it is at equal distance from previous prime (661004838583) and next prime (661004838587).

It can be written as a sum of positive squares in 8 ways, for example, as 93399305769 + 567605532816 = 305613^2 + 753396^2 .

It is not a de Polignac number, because 661004838585 - 2¹ = 661004838583 is a prime.

It is a super-3 number, since 3×661004838585³ (a number of 36 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (661004838581) 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, 8935309 + ... + 9008981.

It is an arithmetic number, because the mean of its divisors is an integer number (9999514161).

Almost surely, 2^661004838585 is an apocalyptic number.

661004838585 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

661004838585 is an abundant number, since it is smaller than the sum of its proper divisors (778925200599).

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

661004838585 is a wasteful number, since it uses less digits than its factorization.

661004838585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74024 (or 74014 counting only the distinct ones).

The product of its (nonzero) digits is 5529600, while the sum is 54.

The spelling of 661004838585 in words is "six hundred sixty-one billion, four million, eight hundred thirty-eight thousand, five hundred eighty-five".