919191816 has 24 divisors (see below), whose sum is σ = 2489478030. Its totient is φ = 306397248.

The previous prime is 919191727. The next prime is 919191817. The reversal of 919191816 is 618191919.

It can be written as a sum of positive squares in only one way, i.e., 648720900 + 270470916 = 25470^2 + 16446^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (919191817) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6383205 + ... + 6383348.

Almost surely, 2^919191816 is an apocalyptic number.

It is an amenable number.

919191816 is an abundant number, since it is smaller than the sum of its proper divisors (1570286214).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

919191816 is a wasteful number, since it uses less digits than its factorization.

919191816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12766565 (or 12766558 counting only the distinct ones).

The product of its digits is 34992, while the sum is 45.

The square root of 919191816 is about 30318.1763303798. The cubic root of 919191816 is about 972.3039490427.

The spelling of 919191816 in words is "nine hundred nineteen million, one hundred ninety-one thousand, eight hundred sixteen".