16836878021 has 2 divisors, whose sum is σ = 16836878022. Its totient is φ = 16836878020.

The previous prime is 16836877927. The next prime is 16836878129. The reversal of 16836878021 is 12087863861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15803255521 + 1033622500 = 125711^2 + 32150^2 .

It is a cyclic number.

It is not a de Polignac number, because 16836878021 - 2¹⁴ = 16836861637 is a prime.

It is a super-2 number, since 2×16836878021² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16836878521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8418439010 + 8418439011.

It is an arithmetic number, because the mean of its divisors is an integer number (8418439011).

Almost surely, 2^16836878021 is an apocalyptic number.

It is an amenable number.

16836878021 is a deficient number, since it is larger than the sum of its proper divisors (1).

16836878021 is an equidigital number, since it uses as much as digits as its factorization.

16836878021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 774144, while the sum is 50.

The spelling of 16836878021 in words is "sixteen billion, eight hundred thirty-six million, eight hundred seventy-eight thousand, twenty-one".