20669767 has 2 divisors, whose sum is σ = 20669768. Its totient is φ = 20669766.

The previous prime is 20669729. The next prime is 20669783. The reversal of 20669767 is 76796602.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20669767 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20669167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10334883 + 10334884.

It is an arithmetic number, because the mean of its divisors is an integer number (10334884).

Almost surely, 2^20669767 is an apocalyptic number.

20669767 is a deficient number, since it is larger than the sum of its proper divisors (1).

20669767 is an equidigital number, since it uses as much as digits as its factorization.

20669767 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 190512, while the sum is 43.

The square root of 20669767 is about 4546.4015440786. The cubic root of 20669767 is about 274.4385990561.

The spelling of 20669767 in words is "twenty million, six hundred sixty-nine thousand, seven hundred sixty-seven".