21880069 has 2 divisors, whose sum is σ = 21880070. Its totient is φ = 21880068.

The previous prime is 21880063. The next prime is 21880073. The reversal of 21880069 is 96008812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20367169 + 1512900 = 4513^2 + 1230^2 .

It is a cyclic number.

It is not a de Polignac number, because 21880069 - 2²³ = 13491461 is a prime.

It is a super-2 number, since 2×21880069² = 957474838889522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21880063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10940034 + 10940035.

It is an arithmetic number, because the mean of its divisors is an integer number (10940035).

Almost surely, 2^21880069 is an apocalyptic number.

It is an amenable number.

21880069 is a deficient number, since it is larger than the sum of its proper divisors (1).

21880069 is an equidigital number, since it uses as much as digits as its factorization.

21880069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 21880069 is about 4677.6136009722. The cubic root of 21880069 is about 279.6938362681.

The spelling of 21880069 in words is "twenty-one million, eight hundred eighty thousand, sixty-nine".