20010243251 has 4 divisors (see below), whose sum is σ = 20041171632. Its totient is φ = 19979314872.

The previous prime is 20010243247. The next prime is 20010243277. The reversal of 20010243251 is 15234201002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15234201002 = 2 ⋅7617100501.

It is a cyclic number.

It is not a de Polignac number, because 20010243251 - 2² = 20010243247 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20010243241) 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, 15463220 + ... + 15464513.

It is an arithmetic number, because the mean of its divisors is an integer number (5010292908).

Almost surely, 2^20010243251 is an apocalyptic number.

20010243251 is a deficient number, since it is larger than the sum of its proper divisors (30928381).

20010243251 is an equidigital number, since it uses as much as digits as its factorization.

20010243251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30928380.

The product of its (nonzero) digits is 480, while the sum is 20.

Adding to 20010243251 its reverse (15234201002), we get a palindrome (35244444253).

The spelling of 20010243251 in words is "twenty billion, ten million, two hundred forty-three thousand, two hundred fifty-one".