2100820806556 has 24 divisors (see below), whose sum is σ = 3693294025344. Its totient is φ = 1045600174320.

The previous prime is 2100820806499. The next prime is 2100820806559. The reversal of 2100820806556 is 6556080280012.

It is a super-2 number, since 2×2100820806556² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100820806559) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 571471 + ... + 2127961.

It is an arithmetic number, because the mean of its divisors is an integer number (153887251056).

Almost surely, 2^{2100820806556} is an apocalyptic number.

It is an amenable number.

2100820806556 is a deficient number, since it is larger than the sum of its proper divisors (1592473218788).

2100820806556 is a wasteful number, since it uses less digits than its factorization.

2100820806556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1558041 (or 1558039 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 43.

The spelling of 2100820806556 in words is "two trillion, one hundred billion, eight hundred twenty million, eight hundred six thousand, five hundred fifty-six".