20211000001993 has 2 divisors, whose sum is σ = 20211000001994. Its totient is φ = 20211000001992.

The previous prime is 20211000001981. The next prime is 20211000002069. The reversal of 20211000001993 is 39910000011202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20209223548089 + 1776453904 = 4495467^2 + 42148^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20211000001993 is a prime.

It is a super-2 number, since 2×20211000001993² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20211001001993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105500000996 + 10105500000997.

It is an arithmetic number, because the mean of its divisors is an integer number (10105500000997).

Almost surely, 2^{20211000001993} is an apocalyptic number.

It is an amenable number.

20211000001993 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211000001993 is an equidigital number, since it uses as much as digits as its factorization.

20211000001993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 28.

The spelling of 20211000001993 in words is "twenty trillion, two hundred eleven billion, one thousand, nine hundred ninety-three".