10420203821 has 2 divisors, whose sum is σ = 10420203822. Its totient is φ = 10420203820.

The previous prime is 10420203811. The next prime is 10420203863. The reversal of 10420203821 is 12830202401.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7045755721 + 3374448100 = 83939^2 + 58090^2 .

It is a cyclic number.

It is not a de Polignac number, because 10420203821 - 2²⁶ = 10353094957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10420203811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5210101910 + 5210101911.

It is an arithmetic number, because the mean of its divisors is an integer number (5210101911).

Almost surely, 2^10420203821 is an apocalyptic number.

It is an amenable number.

10420203821 is a deficient number, since it is larger than the sum of its proper divisors (1).

10420203821 is an equidigital number, since it uses as much as digits as its factorization.

10420203821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 23.

The spelling of 10420203821 in words is "ten billion, four hundred twenty million, two hundred three thousand, eight hundred twenty-one".