97188251921 has 2 divisors, whose sum is σ = 97188251922. Its totient is φ = 97188251920.

The previous prime is 97188251893. The next prime is 97188251947. The reversal of 97188251921 is 12915288179.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 95998346896 + 1189905025 = 309836^2 + 34495^2 .

It is an emirp because it is prime and its reverse (12915288179) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 97188251921 - 2¹⁸ = 97187989777 is a prime.

It is a super-2 number, since 2×97188251921² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (97188251221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48594125960 + 48594125961.

It is an arithmetic number, because the mean of its divisors is an integer number (48594125961).

Almost surely, 2^97188251921 is an apocalyptic number.

It is an amenable number.

97188251921 is a deficient number, since it is larger than the sum of its proper divisors (1).

97188251921 is an equidigital number, since it uses as much as digits as its factorization.

97188251921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 725760, while the sum is 53.

The spelling of 97188251921 in words is "ninety-seven billion, one hundred eighty-eight million, two hundred fifty-one thousand, nine hundred twenty-one".