909191919090 has 256 divisors, whose sum is σ = 2768533447680. Its totient is φ = 185945518080.

The previous prime is 909191919043. The next prime is 909191919107. The reversal of 909191919090 is 90919191909.

It is a self number, because there is not a number n which added to its sum of digits gives 909191919090.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 27154960 + ... + 27188420.

It is an arithmetic number, because the mean of its divisors is an integer number (10814583780).

Almost surely, 2^909191919090 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 909191919090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1384266723840).

909191919090 is an abundant number, since it is smaller than the sum of its proper divisors (1859341528590).

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

909191919090 is a wasteful number, since it uses less digits than its factorization.

909191919090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33797.

The product of its (nonzero) digits is 531441, while the sum is 57.

It can be divided in two parts, 909191 and 919090, that added together give a palindrome (1828281).

The spelling of 909191919090 in words is "nine hundred nine billion, one hundred ninety-one million, nine hundred nineteen thousand, ninety".