2166715620 has 144 divisors (see below), whose sum is σ = 7047855360. Its totient is φ = 536859648.

The previous prime is 2166715601. The next prime is 2166715633. The reversal of 2166715620 is 265176612.

It is a happy number.

2166715620 is a `hidden beast` number, since 2 + 16 + 6 + 7 + 15 + 620 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 237259 + ... + 246221.

It is an arithmetic number, because the mean of its divisors is an integer number (48943440).

Almost surely, 2^2166715620 is an apocalyptic number.

2166715620 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 2166715620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3523927680).

2166715620 is an abundant number, since it is smaller than the sum of its proper divisors (4881139740).

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

2166715620 is a wasteful number, since it uses less digits than its factorization.

2166715620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9074 (or 9069 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 2166715620 is about 46547.9926527450. The cubic root of 2166715620 is about 1293.9990914347. Note that the first 3 decimals are identical.

The spelling of 2166715620 in words is "two billion, one hundred sixty-six million, seven hundred fifteen thousand, six hundred twenty".