20381400 has 216 divisors, whose sum is σ = 75223980. Its totient is φ = 4942080.

The previous prime is 20381399. The next prime is 20381401. The reversal of 20381400 is 418302.

20381400 = T₁₇₉ + T₁₈₀ + ... + T₅₀₃.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20381399) and next prime (20381401).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20381401) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 304167 + ... + 304233.

Almost surely, 2^20381400 is an apocalyptic number.

20381400 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 20381400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37611990).

20381400 is an abundant number, since it is smaller than the sum of its proper divisors (54842580).

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

20381400 is a wasteful number, since it uses less digits than its factorization.

20381400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115 (or 90 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 20381400 is about 4514.5763920882. The cubic root of 20381400 is about 273.1563729983.

Adding to 20381400 its reverse (418302), we get a palindrome (20799702).

The spelling of 20381400 in words is "twenty million, three hundred eighty-one thousand, four hundred".