21656060657029 has 2 divisors, whose sum is σ = 21656060657030. Its totient is φ = 21656060657028.

The previous prime is 21656060656999. The next prime is 21656060657053. The reversal of 21656060657029 is 92075606065612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21092645284929 + 563415372100 = 4592673^2 + 750610^2 .

It is a cyclic number.

It is not a de Polignac number, because 21656060657029 - 2¹³ = 21656060648837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21656060657129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10828030328514 + 10828030328515.

It is an arithmetic number, because the mean of its divisors is an integer number (10828030328515).

Almost surely, 2^{21656060657029} is an apocalyptic number.

It is an amenable number.

21656060657029 is a deficient number, since it is larger than the sum of its proper divisors (1).

21656060657029 is an equidigital number, since it uses as much as digits as its factorization.

21656060657029 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8164800, while the sum is 55.

The spelling of 21656060657029 in words is "twenty-one trillion, six hundred fifty-six billion, sixty million, six hundred fifty-seven thousand, twenty-nine".