91621601 has 4 divisors (see below), whose sum is σ = 91652352. Its totient is φ = 91590852.

The previous prime is 91621571. The next prime is 91621603. The reversal of 91621601 is 10612619.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 10612619 = 991 ⋅10709.

It is a cyclic number.

It is not a de Polignac number, because 91621601 - 2¹⁰ = 91620577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91621603) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10361 + ... + 17046.

It is an arithmetic number, because the mean of its divisors is an integer number (22913088).

Almost surely, 2^91621601 is an apocalyptic number.

It is an amenable number.

91621601 is a deficient number, since it is larger than the sum of its proper divisors (30751).

91621601 is a wasteful number, since it uses less digits than its factorization.

91621601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30750.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 91621601 is about 9571.9173105496. The cubic root of 91621601 is about 450.8159697412.

The spelling of 91621601 in words is "ninety-one million, six hundred twenty-one thousand, six hundred one".