1161515550 has 96 divisors (see below), whose sum is σ = 3132799488. Its totient is φ = 283086720.

The previous prime is 1161515513. The next prime is 1161515557. The reversal of 1161515550 is 555151611.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1161515557) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 197959 + ... + 203741.

It is an arithmetic number, because the mean of its divisors is an integer number (32633328).

Almost surely, 2^1161515550 is an apocalyptic number.

1161515550 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 1161515550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1566399744).

1161515550 is an abundant number, since it is smaller than the sum of its proper divisors (1971283938).

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

1161515550 is a wasteful number, since it uses less digits than its factorization.

1161515550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5914 (or 5909 counting only the distinct ones).

The product of its (nonzero) digits is 3750, while the sum is 30.

The square root of 1161515550 is about 34081.0145095477. The cubic root of 1161515550 is about 1051.1749658841.

The spelling of 1161515550 in words is "one billion, one hundred sixty-one million, five hundred fifteen thousand, five hundred fifty".