20778480 has 60 divisors (see below), whose sum is σ = 69783480. Its totient is φ = 5540736.

The previous prime is 20778473. The next prime is 20778487. The reversal of 20778480 is 8487702.

It is an interprime number because it is at equal distance from previous prime (20778473) and next prime (20778487).

It is a tau number, because it is divible by the number of its divisors (60).

It is a super-2 number, since 2×20778480² = 863490462220800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20778487) 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 11 ways as a sum of consecutive naturals, for example, 13710 + ... + 15149.

It is an arithmetic number, because the mean of its divisors is an integer number (1163058).

Almost surely, 2^20778480 is an apocalyptic number.

20778480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20778480 is an abundant number, since it is smaller than the sum of its proper divisors (49005000).

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

20778480 is a wasteful number, since it uses less digits than its factorization.

20778480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28878 (or 28869 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 36.

The square root of 20778480 is about 4558.3418037703. The cubic root of 20778480 is about 274.9188961932.

It can be divided in two parts, 207 and 78480, that added together give a palindrome (78687).

The spelling of 20778480 in words is "twenty million, seven hundred seventy-eight thousand, four hundred eighty".