91947399 has 8 divisors (see below), whose sum is σ = 127926912. Its totient is φ = 58633080.

The previous prime is 91947397. The next prime is 91947409. The reversal of 91947399 is 99374919.

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

It is not a de Polignac number, because 91947399 - 2¹ = 91947397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91947391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 666217 + ... + 666354.

It is an arithmetic number, because the mean of its divisors is an integer number (15990864).

Almost surely, 2^91947399 is an apocalyptic number.

91947399 is a deficient number, since it is larger than the sum of its proper divisors (35979513).

91947399 is a wasteful number, since it uses less digits than its factorization.

91947399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1332597.

The product of its digits is 551124, while the sum is 51.

The square root of 91947399 is about 9588.9206379029. The cubic root of 91947399 is about 451.3496910163.

The spelling of 91947399 in words is "ninety-one million, nine hundred forty-seven thousand, three hundred ninety-nine".