91359821 has 16 divisors (see below), whose sum is σ = 110297088. Its totient is φ = 74012400.

The previous prime is 91359817. The next prime is 91359833. The reversal of 91359821 is 12895319.

It is not a de Polignac number, because 91359821 - 2² = 91359817 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 (91359811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4436 + ... + 14226.

It is an arithmetic number, because the mean of its divisors is an integer number (6893568).

Almost surely, 2^91359821 is an apocalyptic number.

It is an amenable number.

91359821 is a deficient number, since it is larger than the sum of its proper divisors (18937267).

91359821 is a wasteful number, since it uses less digits than its factorization.

91359821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9872.

The product of its digits is 19440, while the sum is 38.

The square root of 91359821 is about 9558.2331526282. The cubic root of 91359821 is about 450.3862050766.

The spelling of 91359821 in words is "ninety-one million, three hundred fifty-nine thousand, eight hundred twenty-one".