18720829 has 4 divisors (see below), whose sum is σ = 18844960. Its totient is φ = 18596700.

The previous prime is 18720803. The next prime is 18720847. The reversal of 18720829 is 92802781.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18720829 - 2⁵ = 18720797 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 (18723829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61839 + ... + 62140.

It is an arithmetic number, because the mean of its divisors is an integer number (4711240).

Almost surely, 2^18720829 is an apocalyptic number.

It is an amenable number.

18720829 is a deficient number, since it is larger than the sum of its proper divisors (124131).

18720829 is a wasteful number, since it uses less digits than its factorization.

18720829 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124130.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 18720829 is about 4326.7573308426. The cubic root of 18720829 is about 265.5267982829.

The spelling of 18720829 in words is "eighteen million, seven hundred twenty thousand, eight hundred twenty-nine".