78221012197 has 2 divisors, whose sum is σ = 78221012198. Its totient is φ = 78221012196.

The previous prime is 78221012183. The next prime is 78221012213. The reversal of 78221012197 is 79121012287.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72881641156 + 5339371041 = 269966^2 + 73071^2 .

It is a cyclic number.

It is not a de Polignac number, because 78221012197 - 2⁷ = 78221012069 is a prime.

It is a super-2 number, since 2×78221012197² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78221012137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39110506098 + 39110506099.

It is an arithmetic number, because the mean of its divisors is an integer number (39110506099).

Almost surely, 2^78221012197 is an apocalyptic number.

It is an amenable number.

78221012197 is a deficient number, since it is larger than the sum of its proper divisors (1).

78221012197 is an equidigital number, since it uses as much as digits as its factorization.

78221012197 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28224, while the sum is 40.

The spelling of 78221012197 in words is "seventy-eight billion, two hundred twenty-one million, twelve thousand, one hundred ninety-seven".