20309613660 has 288 divisors, whose sum is σ = 71893785600. Its totient is φ = 4544824320.

The previous prime is 20309613659. The next prime is 20309613713. The reversal of 20309613660 is 6631690302.

20309613660 is a `hidden beast` number, since 2 + 0 + 30 + 9 + 613 + 6 + 6 + 0 = 666.

It is a super-3 number, since 3×20309613660³ (a number of 32 digits) contains 333 as substring.

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 95 ways as a sum of consecutive naturals, for example, 26687680 + ... + 26688440.

It is an arithmetic number, because the mean of its divisors is an integer number (249631200).

Almost surely, 2^20309613660 is an apocalyptic number.

20309613660 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 20309613660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35946892800).

20309613660 is an abundant number, since it is smaller than the sum of its proper divisors (51584171940).

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

20309613660 is a wasteful number, since it uses less digits than its factorization.

20309613660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1201 (or 1196 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 36.

The spelling of 20309613660 in words is "twenty billion, three hundred nine million, six hundred thirteen thousand, six hundred sixty".