21236707 has 2 divisors, whose sum is σ = 21236708. Its totient is φ = 21236706.

The previous prime is 21236693. The next prime is 21236713. The reversal of 21236707 is 70763212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21236707 - 2¹⁵ = 21203939 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (21236777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10618353 + 10618354.

It is an arithmetic number, because the mean of its divisors is an integer number (10618354).

Almost surely, 2^21236707 is an apocalyptic number.

21236707 is a deficient number, since it is larger than the sum of its proper divisors (1).

21236707 is an equidigital number, since it uses as much as digits as its factorization.

21236707 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3528, while the sum is 28.

The square root of 21236707 is about 4608.3301748030. The cubic root of 21236707 is about 276.9251449652.

Adding to 21236707 its reverse (70763212), we get a palindrome (91999919).

The spelling of 21236707 in words is "twenty-one million, two hundred thirty-six thousand, seven hundred seven".