91621897 has 8 divisors (see below), whose sum is σ = 93444512. Its totient is φ = 89812800.

The previous prime is 91621883. The next prime is 91621927. The reversal of 91621897 is 79812619.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 91621897 - 2⁷ = 91621769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91621837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10897 + ... + 17377.

It is an arithmetic number, because the mean of its divisors is an integer number (11680564).

Almost surely, 2^91621897 is an apocalyptic number.

It is an amenable number.

91621897 is a deficient number, since it is larger than the sum of its proper divisors (1822615).

91621897 is a wasteful number, since it uses less digits than its factorization.

91621897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6759.

The product of its digits is 54432, while the sum is 43.

The square root of 91621897 is about 9571.9327724342. The cubic root of 91621897 is about 450.8164552213.

The spelling of 91621897 in words is "ninety-one million, six hundred twenty-one thousand, eight hundred ninety-seven".