20778210 has 96 divisors (see below), whose sum is σ = 58968000. Its totient is φ = 5056128.

The previous prime is 20778203. The next prime is 20778211. The reversal of 20778210 is 1287702.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20778211) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 49381 + ... + 49799.

It is an arithmetic number, because the mean of its divisors is an integer number (614250).

Almost surely, 2^20778210 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20778210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29484000).

20778210 is an abundant number, since it is smaller than the sum of its proper divisors (38189790).

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

20778210 is a wasteful number, since it uses less digits than its factorization.

20778210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 480 (or 477 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 27.

The square root of 20778210 is about 4558.3121876414. The cubic root of 20778210 is about 274.9177054031.

The spelling of 20778210 in words is "twenty million, seven hundred seventy-eight thousand, two hundred ten".