20723669 has 2 divisors, whose sum is σ = 20723670. Its totient is φ = 20723668.

The previous prime is 20723639. The next prime is 20723671. The reversal of 20723669 is 96632702.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15602500 + 5121169 = 3950^2 + 2263^2 .

It is a cyclic number.

It is not a de Polignac number, because 20723669 - 2⁸ = 20723413 is a prime.

It is a super-2 number, since 2×20723669² = 858940913643122, which contains 22 as substring.

Together with 20723671, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20723609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10361834 + 10361835.

It is an arithmetic number, because the mean of its divisors is an integer number (10361835).

Almost surely, 2^20723669 is an apocalyptic number.

It is an amenable number.

20723669 is a deficient number, since it is larger than the sum of its proper divisors (1).

20723669 is an equidigital number, since it uses as much as digits as its factorization.

20723669 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27216, while the sum is 35.

The square root of 20723669 is about 4552.3256693694. The cubic root of 20723669 is about 274.6769495776.

The spelling of 20723669 in words is "twenty million, seven hundred twenty-three thousand, six hundred sixty-nine".