20451303247 has 4 divisors (see below), whose sum is σ = 20731458160. Its totient is φ = 20171148336.

The previous prime is 20451303227. The next prime is 20451303307. The reversal of 20451303247 is 74230315402.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74230315402 = 2 ⋅37115157701.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20451303247 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 (20451303227) 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, 140077347 + ... + 140077492.

It is an arithmetic number, because the mean of its divisors is an integer number (5182864540).

Almost surely, 2^20451303247 is an apocalyptic number.

20451303247 is a deficient number, since it is larger than the sum of its proper divisors (280154913).

20451303247 is an equidigital number, since it uses as much as digits as its factorization.

20451303247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280154912.

The product of its (nonzero) digits is 20160, while the sum is 31.

Adding to 20451303247 its reverse (74230315402), we get a palindrome (94681618649).

The spelling of 20451303247 in words is "twenty billion, four hundred fifty-one million, three hundred three thousand, two hundred forty-seven".