21473087 has 2 divisors, whose sum is σ = 21473088. Its totient is φ = 21473086.

The previous prime is 21473071. The next prime is 21473093. The reversal of 21473087 is 78037412.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21473087 - 2⁴ = 21473071 is a prime.

It is a super-2 number, since 2×21473087² = 922186930619138, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21473017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10736543 + 10736544.

It is an arithmetic number, because the mean of its divisors is an integer number (10736544).

Almost surely, 2^21473087 is an apocalyptic number.

21473087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21473087 is an equidigital number, since it uses as much as digits as its factorization.

21473087 is an evil number, because the sum of its binary digits is even.

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

The square root of 21473087 is about 4633.9062355641. The cubic root of 21473087 is about 277.9488156893.

The spelling of 21473087 in words is "twenty-one million, four hundred seventy-three thousand, eighty-seven".