91645421 has 4 divisors (see below), whose sum is σ = 104737632. Its totient is φ = 78553212.

The previous prime is 91645403. The next prime is 91645447. The reversal of 91645421 is 12454619.

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.

It is a cyclic number.

It is not a de Polignac number, because 91645421 - 2⁶ = 91645357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91645921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6546095 + ... + 6546108.

It is an arithmetic number, because the mean of its divisors is an integer number (26184408).

Almost surely, 2^91645421 is an apocalyptic number.

It is an amenable number.

91645421 is a deficient number, since it is larger than the sum of its proper divisors (13092211).

91645421 is a wasteful number, since it uses less digits than its factorization.

91645421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13092210.

The product of its digits is 8640, while the sum is 32.

The square root of 91645421 is about 9573.1614945116. The cubic root of 91645421 is about 450.8550344225.

The spelling of 91645421 in words is "ninety-one million, six hundred forty-five thousand, four hundred twenty-one".