20780329 has 2 divisors, whose sum is σ = 20780330. Its totient is φ = 20780328.

The previous prime is 20780303. The next prime is 20780369. The reversal of 20780329 is 92308702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20475625 + 304704 = 4525^2 + 552^2 .

It is a cyclic number.

It is not a de Polignac number, because 20780329 - 2¹³ = 20772137 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20780329.

It is not a weakly prime, because it can be changed into another prime (20780369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10390164 + 10390165.

It is an arithmetic number, because the mean of its divisors is an integer number (10390165).

Almost surely, 2^20780329 is an apocalyptic number.

It is an amenable number.

20780329 is a deficient number, since it is larger than the sum of its proper divisors (1).

20780329 is an equidigital number, since it uses as much as digits as its factorization.

20780329 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 20780329 is about 4558.5446142382. The cubic root of 20780329 is about 274.9270506228.

The spelling of 20780329 in words is "twenty million, seven hundred eighty thousand, three hundred twenty-nine".