20152381 has 2 divisors, whose sum is σ = 20152382. Its totient is φ = 20152380.

The previous prime is 20152367. The next prime is 20152397. The reversal of 20152381 is 18325102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18922500 + 1229881 = 4350^2 + 1109^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20152381 is a prime.

It is a super-2 number, since 2×20152381² = 812236919938322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20152351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10076190 + 10076191.

It is an arithmetic number, because the mean of its divisors is an integer number (10076191).

Almost surely, 2^20152381 is an apocalyptic number.

It is an amenable number.

20152381 is a deficient number, since it is larger than the sum of its proper divisors (1).

20152381 is an equidigital number, since it uses as much as digits as its factorization.

20152381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 20152381 is about 4489.1403408671. The cubic root of 20152381 is about 272.1293943539.

Adding to 20152381 its reverse (18325102), we get a palindrome (38477483).

The spelling of 20152381 in words is "twenty million, one hundred fifty-two thousand, three hundred eighty-one".