20336381 has 4 divisors (see below), whose sum is σ = 21900732. Its totient is φ = 18772032.

The previous prime is 20336359. The next prime is 20336387. The reversal of 20336381 is 18363302.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18363302 = 2 ⋅9181651.

It can be written as a sum of positive squares in 2 ways, for example, as 8323225 + 12013156 = 2885^2 + 3466^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20336381 is a prime.

It is a super-2 number, since 2×20336381² = 827136784354322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20336381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20336387) 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, 782156 + ... + 782181.

It is an arithmetic number, because the mean of its divisors is an integer number (5475183).

Almost surely, 2^20336381 is an apocalyptic number.

It is an amenable number.

20336381 is a deficient number, since it is larger than the sum of its proper divisors (1564351).

20336381 is a wasteful number, since it uses less digits than its factorization.

20336381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1564350.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 20336381 is about 4509.5876751650. The cubic root of 20336381 is about 272.9551062872.

Adding to 20336381 its reverse (18363302), we get a palindrome (38699683).

It can be divided in two parts, 20336 and 381, that multiplied together give a triangular number (7748016 = T₃₉₃₆).

The spelling of 20336381 in words is "twenty million, three hundred thirty-six thousand, three hundred eighty-one".