21780939227 has 2 divisors, whose sum is σ = 21780939228. Its totient is φ = 21780939226.

The previous prime is 21780939217. The next prime is 21780939239. The reversal of 21780939227 is 72293908712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21780939227 - 2¹⁶ = 21780873691 is a prime.

It is a super-2 number, since 2×21780939227² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21780939217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10890469613 + 10890469614.

It is an arithmetic number, because the mean of its divisors is an integer number (10890469614).

Almost surely, 2^21780939227 is an apocalyptic number.

21780939227 is a deficient number, since it is larger than the sum of its proper divisors (1).

21780939227 is an equidigital number, since it uses as much as digits as its factorization.

21780939227 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 762048, while the sum is 50.

The spelling of 21780939227 in words is "twenty-one billion, seven hundred eighty million, nine hundred thirty-nine thousand, two hundred twenty-seven".