20381946 has 64 divisors (see below), whose sum is σ = 48988800. Its totient is φ = 5584896.

The previous prime is 20381941. The next prime is 20381947. The reversal of 20381946 is 64918302.

20381946 = T₁₅₄₀ + T₁₅₄₁ + ... + T₁₅₅₆.

It is not an unprimeable number, because it can be changed into a prime (20381941) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 24790 + ... + 25598.

It is an arithmetic number, because the mean of its divisors is an integer number (765450).

Almost surely, 2^20381946 is an apocalyptic number.

20381946 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 20381946, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24494400).

20381946 is an abundant number, since it is smaller than the sum of its proper divisors (28606854).

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

20381946 is a wasteful number, since it uses less digits than its factorization.

20381946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 863.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 20381946 is about 4514.6368624730. The cubic root of 20381946 is about 273.1588121838.

The spelling of 20381946 in words is "twenty million, three hundred eighty-one thousand, nine hundred forty-six".