21477913 has 2 divisors, whose sum is σ = 21477914. Its totient is φ = 21477912.

The previous prime is 21477889. The next prime is 21477959. The reversal of 21477913 is 31977412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13816089 + 7661824 = 3717^2 + 2768^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21477913 is a prime.

It is a super-3 number, since 3×21477913³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (21477983) 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, 10738956 + 10738957.

It is an arithmetic number, because the mean of its divisors is an integer number (10738957).

Almost surely, 2^21477913 is an apocalyptic number.

It is an amenable number.

21477913 is a deficient number, since it is larger than the sum of its proper divisors (1).

21477913 is an equidigital number, since it uses as much as digits as its factorization.

21477913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10584, while the sum is 34.

The square root of 21477913 is about 4634.4269332896. The cubic root of 21477913 is about 277.9696367991.

The spelling of 21477913 in words is "twenty-one million, four hundred seventy-seven thousand, nine hundred thirteen".