20801816 has 32 divisors (see below), whose sum is σ = 46116000. Its totient is φ = 8606976.

The previous prime is 20801797. The next prime is 20801839. The reversal of 20801816 is 61810802.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4781 + ... + 8028.

It is an arithmetic number, because the mean of its divisors is an integer number (1441125).

Almost surely, 2^20801816 is an apocalyptic number.

It is an amenable number.

20801816 is an abundant number, since it is smaller than the sum of its proper divisors (25314184).

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

20801816 is a wasteful number, since it uses less digits than its factorization.

20801816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12851 (or 12847 counting only the distinct ones).

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

The square root of 20801816 is about 4560.9007882216. The cubic root of 20801816 is about 275.0217767879.

The spelling of 20801816 in words is "twenty million, eight hundred one thousand, eight hundred sixteen".