2100720655 has 32 divisors (see below), whose sum is σ = 2906668800. Its totient is φ = 1441440000.

The previous prime is 2100720569. The next prime is 2100720683. The reversal of 2100720655 is 5560270012.

It is not a de Polignac number, because 2100720655 - 2⁷ = 2100720527 is a prime.

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, 258291 + ... + 266299.

It is an arithmetic number, because the mean of its divisors is an integer number (90833400).

Almost surely, 2^2100720655 is an apocalyptic number.

2100720655 is a deficient number, since it is larger than the sum of its proper divisors (805948145).

2100720655 is a wasteful number, since it uses less digits than its factorization.

2100720655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8295.

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 2100720655 is about 45833.6192657748. The cubic root of 2100720655 is about 1280.7256332785.

Adding to 2100720655 its reverse (5560270012), we get a palindrome (7660990667).

The spelling of 2100720655 in words is "two billion, one hundred million, seven hundred twenty thousand, six hundred fifty-five".