20699669 has 2 divisors, whose sum is σ = 20699670. Its totient is φ = 20699668.

The previous prime is 20699663. The next prime is 20699671. The reversal of 20699669 is 96699602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17960644 + 2739025 = 4238^2 + 1655^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20699669 is a prime.

It is a super-2 number, since 2×20699669² = 856952593419122, which contains 22 as substring.

Together with 20699671, 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 (20699663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10349834 + 10349835.

It is an arithmetic number, because the mean of its divisors is an integer number (10349835).

Almost surely, 2^20699669 is an apocalyptic number.

It is an amenable number.

20699669 is a deficient number, since it is larger than the sum of its proper divisors (1).

20699669 is an equidigital number, since it uses as much as digits as its factorization.

20699669 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 314928, while the sum is 47.

The square root of 20699669 is about 4549.6888904627. The cubic root of 20699669 is about 274.5708745184.

The spelling of 20699669 in words is "twenty million, six hundred ninety-nine thousand, six hundred sixty-nine".