1171215972 has 18 divisors (see below), whose sum is σ = 2960573798. Its totient is φ = 390405312.

The previous prime is 1171215967. The next prime is 1171215979. The reversal of 1171215972 is 2795121711.

It can be written as a sum of positive squares in only one way, i.e., 1138657536 + 32558436 = 33744^2 + 5706^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 32533777 = 1171215972 / (1 + 1 + 7 + 1 + 2 + 1 + 5 + 9 + 7 + 2).

It is not an unprimeable number, because it can be changed into a prime (1171215979) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16266853 + ... + 16266924.

Almost surely, 2^1171215972 is an apocalyptic number.

1171215972 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1171215972 is an abundant number, since it is smaller than the sum of its proper divisors (1789357826).

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

1171215972 is a wasteful number, since it uses less digits than its factorization.

1171215972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32533787 (or 32533782 counting only the distinct ones).

The product of its digits is 8820, while the sum is 36.

The square root of 1171215972 is about 34223.0327703434. The cubic root of 1171215972 is about 1054.0931605260.

The spelling of 1171215972 in words is "one billion, one hundred seventy-one million, two hundred fifteen thousand, nine hundred seventy-two".