21477089 has 2 divisors, whose sum is σ = 21477090. Its totient is φ = 21477088.

The previous prime is 21477077. The next prime is 21477091. The reversal of 21477089 is 98077412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21086464 + 390625 = 4592^2 + 625^2 .

It is a cyclic number.

It is not a de Polignac number, because 21477089 - 2¹² = 21472993 is a prime.

It is a super-2 number, since 2×21477089² = 922530703827842, which contains 22 as substring.

Together with 21477091, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21477289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10738544 + 10738545.

It is an arithmetic number, because the mean of its divisors is an integer number (10738545).

Almost surely, 2^21477089 is an apocalyptic number.

It is an amenable number.

21477089 is a deficient number, since it is larger than the sum of its proper divisors (1).

21477089 is an equidigital number, since it uses as much as digits as its factorization.

21477089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 21477089 is about 4634.3380325565. The cubic root of 21477089 is about 277.9660819858.

The spelling of 21477089 in words is "twenty-one million, four hundred seventy-seven thousand, eighty-nine".