1155421011 has 8 divisors (see below), whose sum is σ = 1542945024. Its totient is φ = 769088840.

The previous prime is 1155421009. The next prime is 1155421039. The reversal of 1155421011 is 1101245511.

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 1155421011 - 2¹ = 1155421009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1155421061) 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, 295695 + ... + 299576.

It is an arithmetic number, because the mean of its divisors is an integer number (192868128).

Almost surely, 2^1155421011 is an apocalyptic number.

1155421011 is a deficient number, since it is larger than the sum of its proper divisors (387524013).

1155421011 is an equidigital number, since it uses as much as digits as its factorization.

1155421011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 595921.

The product of its (nonzero) digits is 200, while the sum is 21.

The square root of 1155421011 is about 33991.4843894761. The cubic root of 1155421011 is about 1049.3332156620. Note that the first 3 decimals are identical.

Adding to 1155421011 its reverse (1101245511), we get a palindrome (2256666522).

It can be divided in two parts, 1155 and 421011, that multiplied together give a triangular number (486267705 = T₃₁₁₈₅).

The spelling of 1155421011 in words is "one billion, one hundred fifty-five million, four hundred twenty-one thousand, eleven".