21120020029 has 2 divisors, whose sum is σ = 21120020030. Its totient is φ = 21120020028.

The previous prime is 21120019961. The next prime is 21120020069. The reversal of 21120020029 is 92002002112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21104825625 + 15194404 = 145275^2 + 3898^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120020029 - 2⁹ = 21120019517 is a prime.

It is a super-2 number, since 2×21120020029² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21120019988 and 21120020015.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21120020069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560010014 + 10560010015.

It is an arithmetic number, because the mean of its divisors is an integer number (10560010015).

Almost surely, 2^21120020029 is an apocalyptic number.

It is an amenable number.

21120020029 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120020029 is an equidigital number, since it uses as much as digits as its factorization.

21120020029 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 19.

The spelling of 21120020029 in words is "twenty-one billion, one hundred twenty million, twenty thousand, twenty-nine".