21677558893 has 2 divisors, whose sum is σ = 21677558894. Its totient is φ = 21677558892.

The previous prime is 21677558873. The next prime is 21677558921. The reversal of 21677558893 is 39885577612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21408664489 + 268894404 = 146317^2 + 16398^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21677558893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21677558803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10838779446 + 10838779447.

It is an arithmetic number, because the mean of its divisors is an integer number (10838779447).

Almost surely, 2^21677558893 is an apocalyptic number.

It is an amenable number.

21677558893 is a deficient number, since it is larger than the sum of its proper divisors (1).

21677558893 is an equidigital number, since it uses as much as digits as its factorization.

21677558893 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25401600, while the sum is 61.

The spelling of 21677558893 in words is "twenty-one billion, six hundred seventy-seven million, five hundred fifty-eight thousand, eight hundred ninety-three".