20621285833 has 2 divisors, whose sum is σ = 20621285834. Its totient is φ = 20621285832.

The previous prime is 20621285771. The next prime is 20621285891. The reversal of 20621285833 is 33858212602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13075236409 + 7546049424 = 114347^2 + 86868^2 .

It is a cyclic number.

It is not a de Polignac number, because 20621285833 - 2¹³ = 20621277641 is a prime.

It is not a weakly prime, because it can be changed into another prime (20621282833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10310642916 + 10310642917.

It is an arithmetic number, because the mean of its divisors is an integer number (10310642917).

Almost surely, 2^20621285833 is an apocalyptic number.

It is an amenable number.

20621285833 is a deficient number, since it is larger than the sum of its proper divisors (1).

20621285833 is an equidigital number, since it uses as much as digits as its factorization.

20621285833 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 138240, while the sum is 40.

The spelling of 20621285833 in words is "twenty billion, six hundred twenty-one million, two hundred eighty-five thousand, eight hundred thirty-three".