2106221766 has 64 divisors (see below), whose sum is σ = 4948335360. Its totient is φ = 590504960.

The previous prime is 2106221737. The next prime is 2106221779. The reversal of 2106221766 is 6671226012.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 50290 + ... + 82106.

It is an arithmetic number, because the mean of its divisors is an integer number (77317740).

Almost surely, 2^2106221766 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2106221766, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2474167680).

2106221766 is an abundant number, since it is smaller than the sum of its proper divisors (2842113594).

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

2106221766 is a wasteful number, since it uses less digits than its factorization.

2106221766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31909.

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 2106221766 is about 45893.5917748873. The cubic root of 2106221766 is about 1281.8425948782.

Adding to 2106221766 its reverse (6671226012), we get a palindrome (8777447778).

The spelling of 2106221766 in words is "two billion, one hundred six million, two hundred twenty-one thousand, seven hundred sixty-six".