2161636764 has 192 divisors, whose sum is σ = 6268416000. Its totient is φ = 577886400.

The previous prime is 2161636739. The next prime is 2161636781. The reversal of 2161636764 is 4676361612.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 10244619 + ... + 10244829.

It is an arithmetic number, because the mean of its divisors is an integer number (32648000).

Almost surely, 2^2161636764 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2161636764, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3134208000).

2161636764 is an abundant number, since it is smaller than the sum of its proper divisors (4106779236).

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

2161636764 is a wasteful number, since it uses less digits than its factorization.

2161636764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389 (or 373 counting only the distinct ones).

The product of its digits is 217728, while the sum is 42.

The square root of 2161636764 is about 46493.4055969231. The cubic root of 2161636764 is about 1292.9872409467.

The spelling of 2161636764 in words is "two billion, one hundred sixty-one million, six hundred thirty-six thousand, seven hundred sixty-four".