21677040509 has 2 divisors, whose sum is σ = 21677040510. Its totient is φ = 21677040508.

The previous prime is 21677040481. The next prime is 21677040547. The reversal of 21677040509 is 90504077612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21527345284 + 149695225 = 146722^2 + 12235^2 .

It is a cyclic number.

It is not a de Polignac number, because 21677040509 - 2³² = 17382073213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21677040109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10838520254 + 10838520255.

It is an arithmetic number, because the mean of its divisors is an integer number (10838520255).

Almost surely, 2^21677040509 is an apocalyptic number.

It is an amenable number.

21677040509 is a deficient number, since it is larger than the sum of its proper divisors (1).

21677040509 is an equidigital number, since it uses as much as digits as its factorization.

21677040509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 105840, while the sum is 41.

The spelling of 21677040509 in words is "twenty-one billion, six hundred seventy-seven million, forty thousand, five hundred nine".