21423107 has 2 divisors, whose sum is σ = 21423108. Its totient is φ = 21423106.

The previous prime is 21423079. The next prime is 21423119. The reversal of 21423107 is 70132412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21423107 - 2¹² = 21419011 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21423167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10711553 + 10711554.

It is an arithmetic number, because the mean of its divisors is an integer number (10711554).

Almost surely, 2^21423107 is an apocalyptic number.

21423107 is a deficient number, since it is larger than the sum of its proper divisors (1).

21423107 is an equidigital number, since it uses as much as digits as its factorization.

21423107 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 21423107 is about 4628.5102354861. The cubic root of 21423107 is about 277.7330002075.

Adding to 21423107 its reverse (70132412), we get a palindrome (91555519).

The spelling of 21423107 in words is "twenty-one million, four hundred twenty-three thousand, one hundred seven".