91535897401 has 45 divisors (see below), whose sum is σ = 108217022001. Its totient is φ = 77375091456.

The previous prime is 91535897393. The next prime is 91535897407. The reversal of 91535897401 is 10479853519.

The square root of 91535897401 is 302549.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 22 ways, for example, as 43056665001 + 48479232400 = 207501^2 + 220180^2 .

It is not a de Polignac number, because 91535897401 - 2³ = 91535897393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91535897407) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 2473943155 + ... + 2473943191.

Almost surely, 2^91535897401 is an apocalyptic number.

91535897401 is the 302549-th square number.

91535897401 is the 151275-th centered octagonal number.

It is an amenable number.

91535897401 is a deficient number, since it is larger than the sum of its proper divisors (16681124600).

91535897401 is an frugal number, since it uses more digits than its factorization.

91535897401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208 (or 67 counting only the distinct ones).

The product of its (nonzero) digits is 1360800, while the sum is 52.

The spelling of 91535897401 in words is "ninety-one billion, five hundred thirty-five million, eight hundred ninety-seven thousand, four hundred one".