20381407 has 4 divisors (see below), whose sum is σ = 20390616. Its totient is φ = 20372200.

The previous prime is 20381401. The next prime is 20381411. The reversal of 20381407 is 70418302.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20381407 - 2³ = 20381399 is a prime.

It is a Duffinian number.

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 pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 948 + ... + 6454.

It is an arithmetic number, because the mean of its divisors is an integer number (5097654).

Almost surely, 2^20381407 is an apocalyptic number.

20381407 is a deficient number, since it is larger than the sum of its proper divisors (9209).

20381407 is an equidigital number, since it uses as much as digits as its factorization.

20381407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9208.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 20381407 is about 4514.5771673547. The cubic root of 20381407 is about 273.1564042702.

Adding to 20381407 its reverse (70418302), we get a palindrome (90799709).

The spelling of 20381407 in words is "twenty million, three hundred eighty-one thousand, four hundred seven".