20818516 has 6 divisors (see below), whose sum is σ = 36432410. Its totient is φ = 10409256.

The previous prime is 20818487. The next prime is 20818517. The reversal of 20818516 is 61581802.

It can be written as a sum of positive squares in only one way, i.e., 20250000 + 568516 = 4500^2 + 754^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20818517) 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 as a sum of consecutive naturals, namely, 2602311 + ... + 2602318.

Almost surely, 2^20818516 is an apocalyptic number.

It is an amenable number.

20818516 is a deficient number, since it is larger than the sum of its proper divisors (15613894).

20818516 is a wasteful number, since it uses less digits than its factorization.

20818516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5204633 (or 5204631 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 31.

The square root of 20818516 is about 4562.7311996216. The cubic root of 20818516 is about 275.0953542606.

The spelling of 20818516 in words is "twenty million, eight hundred eighteen thousand, five hundred sixteen".