91899819 has 32 divisors (see below), whose sum is σ = 152167680. Its totient is φ = 54331200.

The previous prime is 91899817. The next prime is 91899851.

91899819 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 91899819 - 2¹ = 91899817 is a prime.

It is a super-2 number, since 2×91899819² = 16891153464465522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91899817) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8404 + ... + 15950.

It is an arithmetic number, because the mean of its divisors is an integer number (4755240).

Almost surely, 2^91899819 is an apocalyptic number.

91899819 is a gapful number since it is divisible by the number (99) formed by its first and last digit.

91899819 is a deficient number, since it is larger than the sum of its proper divisors (60267861).

91899819 is a wasteful number, since it uses less digits than its factorization.

91899819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7608 (or 7602 counting only the distinct ones).

The product of its digits is 419904, while the sum is 54.

The square root of 91899819 is about 9586.4393285516. The cubic root of 91899819 is about 451.2718243090.

The spelling of 91899819 in words is "ninety-one million, eight hundred ninety-nine thousand, eight hundred nineteen".