20200211821 has 2 divisors, whose sum is σ = 20200211822. Its totient is φ = 20200211820.

The previous prime is 20200211803. The next prime is 20200211861. The reversal of 20200211821 is 12811200202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10297175625 + 9903036196 = 101475^2 + 99514^2 .

It is a cyclic number.

It is not a de Polignac number, because 20200211821 - 2¹⁵ = 20200179053 is a prime.

It is a super-2 number, since 2×20200211821² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20200211861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10100105910 + 10100105911.

It is an arithmetic number, because the mean of its divisors is an integer number (10100105911).

Almost surely, 2^20200211821 is an apocalyptic number.

It is an amenable number.

20200211821 is a deficient number, since it is larger than the sum of its proper divisors (1).

20200211821 is an equidigital number, since it uses as much as digits as its factorization.

20200211821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 19.

The spelling of 20200211821 in words is "twenty billion, two hundred million, two hundred eleven thousand, eight hundred twenty-one".