21200111021986 has 16 divisors (see below), whose sum is σ = 34246457804664. Its totient is φ = 9784631021184.

The previous prime is 21200111021983. The next prime is 21200111022011. The reversal of 21200111021986 is 68912011100212.

It can be written as a sum of positive squares in 4 ways, for example, as 12786810498225 + 8413300523761 = 3575865^2 + 2900569^2 .

It is not an unprimeable number, because it can be changed into a prime (21200111021983) 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, 6638020 + ... + 9298576.

Almost surely, 2^{21200111021986} is an apocalyptic number.

21200111021986 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21200111021986 is a deficient number, since it is larger than the sum of its proper divisors (13046346782678).

21200111021986 is a wasteful number, since it uses less digits than its factorization.

21200111021986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2967045.

The product of its (nonzero) digits is 3456, while the sum is 34.

The spelling of 21200111021986 in words is "twenty-one trillion, two hundred billion, one hundred eleven million, twenty-one thousand, nine hundred eighty-six".