91970497 has 2 divisors, whose sum is σ = 91970498. Its totient is φ = 91970496.

The previous prime is 91970471. The next prime is 91970509. The reversal of 91970497 is 79407919.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51825601 + 40144896 = 7199^2 + 6336^2 .

It is an emirp because it is prime and its reverse (79407919) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91970497 - 2¹¹ = 91968449 is a prime.

It is a super-3 number, since 3×91970497³ (a number of 25 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (91970447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45985248 + 45985249.

It is an arithmetic number, because the mean of its divisors is an integer number (45985249).

Almost surely, 2^91970497 is an apocalyptic number.

It is an amenable number.

91970497 is a deficient number, since it is larger than the sum of its proper divisors (1).

91970497 is an equidigital number, since it uses as much as digits as its factorization.

91970497 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 142884, while the sum is 46.

The square root of 91970497 is about 9590.1249731169. The cubic root of 91970497 is about 451.3874821970.

Subtracting from 91970497 its reverse (79407919), we obtain a triangular number (12562578 = T₅₀₁₂).

The spelling of 91970497 in words is "ninety-one million, nine hundred seventy thousand, four hundred ninety-seven".