20678784 has 128 divisors (see below), whose sum is σ = 64464000. Its totient is φ = 5870592.

The previous prime is 20678741. The next prime is 20678807. The reversal of 20678784 is 48787602.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×20678784² = 855224215437312, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 131634 + ... + 131790.

It is an arithmetic number, because the mean of its divisors is an integer number (503625).

Almost surely, 2^20678784 is an apocalyptic number.

20678784 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20678784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32232000).

20678784 is an abundant number, since it is smaller than the sum of its proper divisors (43785216).

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

20678784 is an equidigital number, since it uses as much as digits as its factorization.

20678784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195 (or 169 counting only the distinct ones).

The product of its (nonzero) digits is 150528, while the sum is 42.

The square root of 20678784 is about 4547.3930993482. The cubic root of 20678784 is about 274.4785003782.

The spelling of 20678784 in words is "twenty million, six hundred seventy-eight thousand, seven hundred eighty-four".