21906707 has 2 divisors, whose sum is σ = 21906708. Its totient is φ = 21906706.

The previous prime is 21906697. The next prime is 21906719. The reversal of 21906707 is 70760912.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21906707 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21906757) 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, 10953353 + 10953354.

It is an arithmetic number, because the mean of its divisors is an integer number (10953354).

Almost surely, 2^21906707 is an apocalyptic number.

21906707 is a deficient number, since it is larger than the sum of its proper divisors (1).

21906707 is an equidigital number, since it uses as much as digits as its factorization.

21906707 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5292, while the sum is 32.

The square root of 21906707 is about 4680.4601269533. The cubic root of 21906707 is about 279.8072951259.

The spelling of 21906707 in words is "twenty-one million, nine hundred six thousand, seven hundred seven".