20278830 has 128 divisors (see below), whose sum is σ = 59512320. Its totient is φ = 4354560.

The previous prime is 20278799. The next prime is 20278837. The reversal of 20278830 is 3887202.

It is a super-2 number, since 2×20278830² = 822461892337800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20278837) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 124329 + ... + 124491.

It is an arithmetic number, because the mean of its divisors is an integer number (464940).

Almost surely, 2^20278830 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20278830, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29756160).

20278830 is an abundant number, since it is smaller than the sum of its proper divisors (39233490).

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

20278830 is a wasteful number, since it uses less digits than its factorization.

20278830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226.

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 20278830 is about 4503.2021939948. The cubic root of 20278830 is about 272.6973796529.

The spelling of 20278830 in words is "twenty million, two hundred seventy-eight thousand, eight hundred thirty".