661585084290 has 160 divisors (see below), whose sum is σ = 1938853578816. Its totient is φ = 160889431680.

The previous prime is 661585084273. The next prime is 661585084367. The reversal of 661585084290 is 92480585166.

661585084290 is a `hidden beast` number, since 6 + 6 + 1 + 5 + 8 + 508 + 42 + 90 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 495505 + ... + 1252475.

Almost surely, 2^661585084290 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661585084290, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (969426789408).

661585084290 is an abundant number, since it is smaller than the sum of its proper divisors (1277268494526).

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

661585084290 is a wasteful number, since it uses less digits than its factorization.

661585084290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 757086 (or 757077 counting only the distinct ones).

The product of its (nonzero) digits is 4147200, while the sum is 54.

The spelling of 661585084290 in words is "six hundred sixty-one billion, five hundred eighty-five million, eighty-four thousand, two hundred ninety".