15121812197 has 2 divisors, whose sum is σ = 15121812198. Its totient is φ = 15121812196.

The previous prime is 15121812157. The next prime is 15121812217. The reversal of 15121812197 is 79121812151.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11744923876 + 3376888321 = 108374^2 + 58111^2 .

It is a cyclic number.

It is not a de Polignac number, because 15121812197 - 2⁶ = 15121812133 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 15121812197.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15121812157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7560906098 + 7560906099.

It is an arithmetic number, because the mean of its divisors is an integer number (7560906099).

Almost surely, 2^15121812197 is an apocalyptic number.

It is an amenable number.

15121812197 is a deficient number, since it is larger than the sum of its proper divisors (1).

15121812197 is an equidigital number, since it uses as much as digits as its factorization.

15121812197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10080, while the sum is 38.

The spelling of 15121812197 in words is "fifteen billion, one hundred twenty-one million, eight hundred twelve thousand, one hundred ninety-seven".