20211220247 has 2 divisors, whose sum is σ = 20211220248. Its totient is φ = 20211220246.

The previous prime is 20211220213. The next prime is 20211220277. The reversal of 20211220247 is 74202211202.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20211220247 - 2¹⁴ = 20211203863 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20211220277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105610123 + 10105610124.

It is an arithmetic number, because the mean of its divisors is an integer number (10105610124).

Almost surely, 2^20211220247 is an apocalyptic number.

20211220247 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211220247 is an equidigital number, since it uses as much as digits as its factorization.

20211220247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 896, while the sum is 23.

Adding to 20211220247 its reverse (74202211202), we get a palindrome (94413431449).

The spelling of 20211220247 in words is "twenty billion, two hundred eleven million, two hundred twenty thousand, two hundred forty-seven".