1656321660 has 144 divisors (see below), whose sum is σ = 5940043200. Its totient is φ = 365524992.

The previous prime is 1656321647. The next prime is 1656321671. The reversal of 1656321660 is 661236561.

1656321660 is a `hidden beast` number, since 1 + 6 + 5 + 632 + 16 + 6 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 13876 + ... + 59204.

It is an arithmetic number, because the mean of its divisors is an integer number (41250300).

Almost surely, 2^1656321660 is an apocalyptic number.

1656321660 is a gapful number since it is divisible by the number (10) 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 1656321660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2970021600).

1656321660 is an abundant number, since it is smaller than the sum of its proper divisors (4283721540).

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

1656321660 is a wasteful number, since it uses less digits than its factorization.

1656321660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45380 (or 45375 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 1656321660 is about 40697.9318884879. The cubic root of 1656321660 is about 1183.1729361825.

The spelling of 1656321660 in words is "one billion, six hundred fifty-six million, three hundred twenty-one thousand, six hundred sixty".