20727780 has 24 divisors (see below), whose sum is σ = 58037952. Its totient is φ = 5527392.

The previous prime is 20727757. The next prime is 20727827. The reversal of 20727780 is 8772702.

It is a happy number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 172672 + ... + 172791.

It is an arithmetic number, because the mean of its divisors is an integer number (2418248).

Almost surely, 2^20727780 is an apocalyptic number.

20727780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20727780 is an abundant number, since it is smaller than the sum of its proper divisors (37310172).

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

20727780 is a wasteful number, since it uses less digits than its factorization.

20727780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345475 (or 345473 counting only the distinct ones).

The product of its (nonzero) digits is 10976, while the sum is 33.

The square root of 20727780 is about 4552.7771744288. Note that the first 3 decimals coincide. The cubic root of 20727780 is about 274.6951111345.

The spelling of 20727780 in words is "twenty million, seven hundred twenty-seven thousand, seven hundred eighty".