1091288121 has 64 divisors (see below), whose sum is σ = 1853300736. Its totient is φ = 554803200.

The previous prime is 1091288117. The next prime is 1091288129. The reversal of 1091288121 is 1218821901.

It is not a de Polignac number, because 1091288121 - 2² = 1091288117 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (1091288129) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2531776 + ... + 2532206.

It is an arithmetic number, because the mean of its divisors is an integer number (28957824).

Almost surely, 2^1091288121 is an apocalyptic number.

1091288121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1091288121 is a deficient number, since it is larger than the sum of its proper divisors (762012615).

1091288121 is a wasteful number, since it uses less digits than its factorization.

1091288121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 662.

The product of its (nonzero) digits is 2304, while the sum is 33.

The square root of 1091288121 is about 33034.6503084262. The cubic root of 1091288121 is about 1029.5477075992.

The spelling of 1091288121 in words is "one billion, ninety-one million, two hundred eighty-eight thousand, one hundred twenty-one".