1091520990 has 96 divisors (see below), whose sum is σ = 3251529216. Its totient is φ = 248863680.

The previous prime is 1091520977. The next prime is 1091521021. The reversal of 1091520990 is 990251901.

It is a super-2 number, since 2×1091520990² = 2382836143221160200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 277135 + ... + 281045.

It is an arithmetic number, because the mean of its divisors is an integer number (33870096).

Almost surely, 2^1091520990 is an apocalyptic number.

1091520990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1091520990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1625764608).

1091520990 is an abundant number, since it is smaller than the sum of its proper divisors (2160008226).

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

1091520990 is a wasteful number, since it uses less digits than its factorization.

1091520990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4374 (or 4371 counting only the distinct ones).

The product of its (nonzero) digits is 7290, while the sum is 36.

The square root of 1091520990 is about 33038.1747377182. The cubic root of 1091520990 is about 1029.6209338137.

The spelling of 1091520990 in words is "one billion, ninety-one million, five hundred twenty thousand, nine hundred ninety".