21066607 has 2 divisors, whose sum is σ = 21066608. Its totient is φ = 21066606.

The previous prime is 21066601. The next prime is 21066613. The reversal of 21066607 is 70666012.

It is a balanced prime because it is at equal distance from previous prime (21066601) and next prime (21066613).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21066607 is a prime.

It is a super-5 number, since 5×21066607⁵ (a number of 38 digits) contains 55555 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21066601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10533303 + 10533304.

It is an arithmetic number, because the mean of its divisors is an integer number (10533304).

Almost surely, 2^21066607 is an apocalyptic number.

21066607 is a deficient number, since it is larger than the sum of its proper divisors (1).

21066607 is an equidigital number, since it uses as much as digits as its factorization.

21066607 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 21066607 is about 4589.8373609530. The cubic root of 21066607 is about 276.1837981451.

The spelling of 21066607 in words is "twenty-one million, sixty-six thousand, six hundred seven".