20066639 has 2 divisors, whose sum is σ = 20066640. Its totient is φ = 20066638.

The previous prime is 20066633. The next prime is 20066687. The reversal of 20066639 is 93666002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20066639 - 2⁴ = 20066623 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20066633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10033319 + 10033320.

It is an arithmetic number, because the mean of its divisors is an integer number (10033320).

Almost surely, 2^20066639 is an apocalyptic number.

20066639 is a deficient number, since it is larger than the sum of its proper divisors (1).

20066639 is an equidigital number, since it uses as much as digits as its factorization.

20066639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 32.

The square root of 20066639 is about 4479.5802258694. The cubic root of 20066639 is about 271.7429042353.

The spelling of 20066639 in words is "twenty million, sixty-six thousand, six hundred thirty-nine".