20601780 has 48 divisors (see below), whose sum is σ = 58242240. Its totient is φ = 5440768.

The previous prime is 20601769. The next prime is 20601781. The reversal of 20601780 is 8710602.

It is a self number, because there is not a number n which added to its sum of digits gives 20601780.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20601781) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4816 + ... + 8024.

It is an arithmetic number, because the mean of its divisors is an integer number (1213380).

Almost surely, 2^20601780 is an apocalyptic number.

20601780 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 20601780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29121120).

20601780 is an abundant number, since it is smaller than the sum of its proper divisors (37640460).

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

20601780 is a wasteful number, since it uses less digits than its factorization.

20601780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3328 (or 3326 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 20601780 is about 4538.9183733572. The cubic root of 20601780 is about 274.1373740606.

The spelling of 20601780 in words is "twenty million, six hundred one thousand, seven hundred eighty".