1091228861 has 8 divisors (see below), whose sum is σ = 1192690944. Its totient is φ = 993908160.

The previous prime is 1091228857. The next prime is 1091228863. The reversal of 1091228861 is 1688221901.

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

It is a cyclic number.

It is not a de Polignac number, because 1091228861 - 2² = 1091228857 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091228863) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1034795 + ... + 1035848.

It is an arithmetic number, because the mean of its divisors is an integer number (149086368).

Almost surely, 2^1091228861 is an apocalyptic number.

It is an amenable number.

1091228861 is a deficient number, since it is larger than the sum of its proper divisors (101462083).

1091228861 is a wasteful number, since it uses less digits than its factorization.

1091228861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2070691.

The product of its (nonzero) digits is 13824, while the sum is 38.

The square root of 1091228861 is about 33033.7533592536. The cubic root of 1091228861 is about 1029.5290714877.

The spelling of 1091228861 in words is "one billion, ninety-one million, two hundred twenty-eight thousand, eight hundred sixty-one".