20647389 has 8 divisors (see below), whose sum is σ = 31462720. Its totient is φ = 11798496.

The previous prime is 20647387. The next prime is 20647409. The reversal of 20647389 is 98374602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20647389 - 2¹ = 20647387 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20647387) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 491584 + ... + 491625.

It is an arithmetic number, because the mean of its divisors is an integer number (3932840).

Almost surely, 2^20647389 is an apocalyptic number.

It is an amenable number.

20647389 is a deficient number, since it is larger than the sum of its proper divisors (10815331).

20647389 is an equidigital number, since it uses as much as digits as its factorization.

20647389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 983219.

The product of its (nonzero) digits is 72576, while the sum is 39.

The square root of 20647389 is about 4543.9398103408. The cubic root of 20647389 is about 274.3395235220.

It can be divided in two parts, 2064 and 7389, that added together give a triangular number (9453 = T₁₃₇).

The spelling of 20647389 in words is "twenty million, six hundred forty-seven thousand, three hundred eighty-nine".