20618766 has 32 divisors (see below), whose sum is σ = 52366080. Its totient is φ = 5890968.

The previous prime is 20618761. The next prime is 20618791. The reversal of 20618766 is 66781602.

It is a happy number.

It is a super-2 number, since 2×20618766² = 850267022725512, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20618766.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20618761) 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 15 ways as a sum of consecutive naturals, for example, 26896 + ... + 27651.

It is an arithmetic number, because the mean of its divisors is an integer number (1636440).

Almost surely, 2^20618766 is an apocalyptic number.

20618766 is an abundant number, since it is smaller than the sum of its proper divisors (31747314).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20618766 is a wasteful number, since it uses less digits than its factorization.

20618766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54565 (or 54559 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 20618766 is about 4540.7891384648. The cubic root of 20618766 is about 274.2126947089.

The spelling of 20618766 in words is "twenty million, six hundred eighteen thousand, seven hundred sixty-six".