2106557720 has 64 divisors (see below), whose sum is σ = 5093578080. Its totient is φ = 781203456.

The previous prime is 2106557701. The next prime is 2106557729. The reversal of 2106557720 is 277556012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2106557729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22442 + ... + 68678.

Almost surely, 2^2106557720 is an apocalyptic number.

2106557720 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 2106557720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2546789040).

2106557720 is an abundant number, since it is smaller than the sum of its proper divisors (2987020360).

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

2106557720 is a wasteful number, since it uses less digits than its factorization.

2106557720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46332 (or 46328 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 35.

The square root of 2106557720 is about 45897.2517695777. The cubic root of 2106557720 is about 1281.9107449119.

The spelling of 2106557720 in words is "two billion, one hundred six million, five hundred fifty-seven thousand, seven hundred twenty".