21636546859 has 2 divisors, whose sum is σ = 21636546860. Its totient is φ = 21636546858.

The previous prime is 21636546853. The next prime is 21636546871. The reversal of 21636546859 is 95864563612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21636546859 - 2²⁵ = 21602992427 is a prime.

It is a super-3 number, since 3×21636546859³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21636546853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10818273429 + 10818273430.

It is an arithmetic number, because the mean of its divisors is an integer number (10818273430).

Almost surely, 2^21636546859 is an apocalyptic number.

21636546859 is a deficient number, since it is larger than the sum of its proper divisors (1).

21636546859 is an equidigital number, since it uses as much as digits as its factorization.

21636546859 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9331200, while the sum is 55.

The spelling of 21636546859 in words is "twenty-one billion, six hundred thirty-six million, five hundred forty-six thousand, eight hundred fifty-nine".