20381264 has 20 divisors (see below), whose sum is σ = 40453140. Its totient is φ = 9941760.

The previous prime is 20381261. The next prime is 20381279. The reversal of 20381264 is 46218302.

It can be written as a sum of positive squares in 2 ways, for example, as 5326864 + 15054400 = 2308^2 + 3880^2 .

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20381261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14879 + ... + 16190.

It is an arithmetic number, because the mean of its divisors is an integer number (2022657).

Almost surely, 2^20381264 is an apocalyptic number.

It is an amenable number.

20381264 is a deficient number, since it is larger than the sum of its proper divisors (20071876).

20381264 is a wasteful number, since it uses less digits than its factorization.

20381264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31118 (or 31112 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 20381264 is about 4514.5613297418. The cubic root of 20381264 is about 273.1557654288.

Adding to 20381264 its reverse (46218302), we get a palindrome (66599566).

The spelling of 20381264 in words is "twenty million, three hundred eighty-one thousand, two hundred sixty-four".