1191281 has 24 divisors (see below), whose sum is σ = 1581120. Its totient is φ = 876096.

The previous prime is 1191277. The next prime is 1191283. The reversal of 1191281 is 1821911.

1191281 = 49² + 50² + ... + 154².

It is not a de Polignac number, because 1191281 - 2² = 1191277 is a prime.

It is a super-2 number, since 2×1191281² = 2838300841922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1191283) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22451 + ... + 22503.

It is an arithmetic number, because the mean of its divisors is an integer number (65880).

2^1191281 is an apocalyptic number.

It is an amenable number.

1191281 is a deficient number, since it is larger than the sum of its proper divisors (389839).

1191281 is a wasteful number, since it uses less digits than its factorization.

1191281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105 (or 92 counting only the distinct ones).

The product of its digits is 144, while the sum is 23.

The square root of 1191281 is about 1091.4581989247. The cubic root of 1191281 is about 106.0078610522.

The spelling of 1191281 in words is "one million, one hundred ninety-one thousand, two hundred eighty-one".