20577920 has 128 divisors (see below), whose sum is σ = 55814400. Its totient is φ = 7188480.

The previous prime is 20577901. The next prime is 20577959. The reversal of 20577920 is 2977502.

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

It is a Harshad number since it is a multiple of its sum of digits (32).

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 15 ways as a sum of consecutive naturals, for example, 260441 + ... + 260519.

It is an arithmetic number, because the mean of its divisors is an integer number (436050).

Almost surely, 2^20577920 is an apocalyptic number.

20577920 is a gapful number since it is divisible by the number (20) 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 20577920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27907200).

20577920 is an abundant number, since it is smaller than the sum of its proper divisors (35236480).

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

20577920 is a wasteful number, since it uses less digits than its factorization.

20577920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146 (or 134 counting only the distinct ones).

The product of its (nonzero) digits is 8820, while the sum is 32.

The square root of 20577920 is about 4536.2892324013. The cubic root of 20577920 is about 274.0315022298.

It can be divided in two parts, 205 and 77920, that added together give a 7-th power (78125 = 5⁷).

The spelling of 20577920 in words is "twenty million, five hundred seventy-seven thousand, nine hundred twenty".