20102381 has 12 divisors (see below), whose sum is σ = 23051412. Its totient is φ = 17462016.

The previous prime is 20102321. The next prime is 20102389. The reversal of 20102381 is 18320102.

It can be written as a sum of positive squares in 6 ways, for example, as 2175625 + 17926756 = 1475^2 + 4234^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20102381 is a prime.

It is a super-2 number, since 2×20102381² = 808211443738322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20102389) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 626 + ... + 6371.

It is an arithmetic number, because the mean of its divisors is an integer number (1920951).

Almost surely, 2^20102381 is an apocalyptic number.

It is an amenable number.

20102381 is a deficient number, since it is larger than the sum of its proper divisors (2949031).

20102381 is a wasteful number, since it uses less digits than its factorization.

20102381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7040 (or 7027 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 20102381 is about 4483.5678872969. The cubic root of 20102381 is about 271.9041482114.

Adding to 20102381 its reverse (18320102), we get a palindrome (38422483).

The spelling of 20102381 in words is "twenty million, one hundred two thousand, three hundred eighty-one".