18820061 has 8 divisors (see below), whose sum is σ = 20399064. Its totient is φ = 17259840.

The previous prime is 18820031. The next prime is 18820063. The reversal of 18820061 is 16002881.

It can be written as a sum of positive squares in 4 ways, for example, as 2059225 + 16760836 = 1435^2 + 4094^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-18820061 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18820061.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18820063) 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, 2570 + ... + 6651.

It is an arithmetic number, because the mean of its divisors is an integer number (2549883).

Almost surely, 2^18820061 is an apocalyptic number.

It is an amenable number.

18820061 is a deficient number, since it is larger than the sum of its proper divisors (1579003).

18820061 is a wasteful number, since it uses less digits than its factorization.

18820061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9391.

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 18820061 is about 4338.2094232529. The cubic root of 18820061 is about 265.9951239990.

The spelling of 18820061 in words is "eighteen million, eight hundred twenty thousand, sixty-one".