21475697 has 2 divisors, whose sum is σ = 21475698. Its totient is φ = 21475696.

The previous prime is 21475687. The next prime is 21475717. The reversal of 21475697 is 79657412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12737761 + 8737936 = 3569^2 + 2956^2 .

It is a cyclic number.

It is not a de Polignac number, because 21475697 - 2⁶ = 21475633 is a prime.

It is a super-2 number, since 2×21475697² = 922411123271618, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21475637) 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, 10737848 + 10737849.

It is an arithmetic number, because the mean of its divisors is an integer number (10737849).

Almost surely, 2^21475697 is an apocalyptic number.

It is an amenable number.

21475697 is a deficient number, since it is larger than the sum of its proper divisors (1).

21475697 is an equidigital number, since it uses as much as digits as its factorization.

21475697 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 105840, while the sum is 41.

The square root of 21475697 is about 4634.1878468616. The cubic root of 21475697 is about 277.9600765608.

The spelling of 21475697 in words is "twenty-one million, four hundred seventy-five thousand, six hundred ninety-seven".