21959044729 has 2 divisors, whose sum is σ = 21959044730. Its totient is φ = 21959044728.

The previous prime is 21959044697. The next prime is 21959044769. The reversal of 21959044729 is 92744095912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20989345129 + 969699600 = 144877^2 + 31140^2 .

It is a cyclic number.

It is not a de Polignac number, because 21959044729 - 2⁵ = 21959044697 is a prime.

It is not a weakly prime, because it can be changed into another prime (21959044769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10979522364 + 10979522365.

It is an arithmetic number, because the mean of its divisors is an integer number (10979522365).

Almost surely, 2^21959044729 is an apocalyptic number.

It is an amenable number.

21959044729 is a deficient number, since it is larger than the sum of its proper divisors (1).

21959044729 is an equidigital number, since it uses as much as digits as its factorization.

21959044729 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1632960, while the sum is 52.

The spelling of 21959044729 in words is "twenty-one billion, nine hundred fifty-nine million, forty-four thousand, seven hundred twenty-nine".