91640199377381 has 2 divisors, whose sum is σ = 91640199377382. Its totient is φ = 91640199377380.

The previous prime is 91640199377333. The next prime is 91640199377411. The reversal of 91640199377381 is 18377399104619.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 89055930933025 + 2584268444356 = 9436945^2 + 1607566^2 .

It is a cyclic number.

It is not a de Polignac number, because 91640199377381 - 2¹⁸ = 91640199115237 is a prime.

It is a super-2 number, since 2×91640199377381² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91640199347381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45820099688690 + 45820099688691.

It is an arithmetic number, because the mean of its divisors is an integer number (45820099688691).

Almost surely, 2^{91640199377381} is an apocalyptic number.

It is an amenable number.

91640199377381 is a deficient number, since it is larger than the sum of its proper divisors (1).

91640199377381 is an equidigital number, since it uses as much as digits as its factorization.

91640199377381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 61725888, while the sum is 68.

The spelling of 91640199377381 in words is "ninety-one trillion, six hundred forty billion, one hundred ninety-nine million, three hundred seventy-seven thousand, three hundred eighty-one".