20101243 has 4 divisors (see below), whose sum is σ = 20134440. Its totient is φ = 20068048.

The previous prime is 20101229. The next prime is 20101247. The reversal of 20101243 is 34210102.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20101243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20101247) 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, 15673 + ... + 16906.

It is an arithmetic number, because the mean of its divisors is an integer number (5033610).

Almost surely, 2^20101243 is an apocalyptic number.

20101243 is the 2397-th centered heptagonal number.

20101243 is a deficient number, since it is larger than the sum of its proper divisors (33197).

20101243 is an equidigital number, since it uses as much as digits as its factorization.

20101243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33196.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 20101243 is about 4483.4409776421. The cubic root of 20101243 is about 271.8990172644.

Adding to 20101243 its reverse (34210102), we get a palindrome (54311345).

The spelling of 20101243 in words is "twenty million, one hundred one thousand, two hundred forty-three".