20121221249 has 2 divisors, whose sum is σ = 20121221250.
Its totient is φ = 20121221248.
The previous prime is 20121221161. The next prime is 20121221303. The reversal of 20121221249 is 94212212102.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 19156497649 + 964723600 = 138407^2 + 31060^2
It is a cyclic number.
It is not a de Polignac number, because 20121221249 - 216 = 20121155713 is a prime.
It is not a weakly prime, because it can be changed into another prime (20121223249) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060610624 + 10060610625.
It is an arithmetic number, because the mean of its divisors is an integer number (10060610625).
Almost surely, 220121221249 is an apocalyptic number.
It is an amenable number.
20121221249 is a deficient number, since it is larger than the sum of its proper divisors (1).
20121221249 is an equidigital number, since it uses as much as digits as its factorization.
20121221249 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 1152, while the sum is 26.
The spelling of 20121221249 in words is "twenty billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred forty-nine".