16780385 has 8 divisors (see below), whose sum is σ = 20241960. Its totient is φ = 13353984.

The previous prime is 16780381. The next prime is 16780391. The reversal of 16780385 is 58308761.

16780385 = T₈₀ + T₈₁ + ... + T₄₆₅.

It can be written as a sum of positive squares in 4 ways, for example, as 1067089 + 15713296 = 1033^2 + 3964^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 16780385 - 2² = 16780381 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16780381) 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, 7730 + ... + 9659.

It is an arithmetic number, because the mean of its divisors is an integer number (2530245).

Almost surely, 2^16780385 is an apocalyptic number.

It is an amenable number.

16780385 is a deficient number, since it is larger than the sum of its proper divisors (3461575).

16780385 is a wasteful number, since it uses less digits than its factorization.

16780385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17587.

The product of its (nonzero) digits is 40320, while the sum is 38.

The square root of 16780385 is about 4096.3868225547. The cubic root of 16780385 is about 256.0161173528.

The spelling of 16780385 in words is "sixteen million, seven hundred eighty thousand, three hundred eighty-five".