21021011043959 has 2 divisors, whose sum is σ = 21021011043960. Its totient is φ = 21021011043958.

The previous prime is 21021011043943. The next prime is 21021011044037. The reversal of 21021011043959 is 95934011012012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21021011043959 - 2⁴ = 21021011043943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21021011033959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510505521979 + 10510505521980.

It is an arithmetic number, because the mean of its divisors is an integer number (10510505521980).

Almost surely, 2^{21021011043959} is an apocalyptic number.

21021011043959 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021011043959 is an equidigital number, since it uses as much as digits as its factorization.

21021011043959 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 38.

The spelling of 21021011043959 in words is "twenty-one trillion, twenty-one billion, eleven million, forty-three thousand, nine hundred fifty-nine".