21473807 has 2 divisors, whose sum is σ = 21473808. Its totient is φ = 21473806.

The previous prime is 21473797. The next prime is 21473821. The reversal of 21473807 is 70837412.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21473807 - 2¹⁰ = 21472783 is a prime.

It is a super-2 number, since 2×21473807² = 922248774146498, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21473827) 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, 10736903 + 10736904.

It is an arithmetic number, because the mean of its divisors is an integer number (10736904).

Almost surely, 2^21473807 is an apocalyptic number.

21473807 is a deficient number, since it is larger than the sum of its proper divisors (1).

21473807 is an equidigital number, since it uses as much as digits as its factorization.

21473807 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9408, while the sum is 32.

The square root of 21473807 is about 4633.9839231486. The cubic root of 21473807 is about 277.9519222277.

The spelling of 21473807 in words is "twenty-one million, four hundred seventy-three thousand, eight hundred seven".