20778520 has 32 divisors (see below), whose sum is σ = 53431200. Its totient is φ = 7123968.

The previous prime is 20778517. The next prime is 20778521. The reversal of 20778520 is 2587702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20778521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36825 + ... + 37384.

It is an arithmetic number, because the mean of its divisors is an integer number (1669725).

Almost surely, 2^20778520 is an apocalyptic number.

20778520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20778520 is an abundant number, since it is smaller than the sum of its proper divisors (32652680).

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

20778520 is a wasteful number, since it uses less digits than its factorization.

20778520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74227 (or 74223 counting only the distinct ones).

The product of its (nonzero) digits is 7840, while the sum is 31.

The square root of 20778520 is about 4558.3461913286. The cubic root of 20778520 is about 274.9190726056.

The spelling of 20778520 in words is "twenty million, seven hundred seventy-eight thousand, five hundred twenty".