1155545961 has 4 divisors (see below), whose sum is σ = 1540727952. Its totient is φ = 770363972.

The previous prime is 1155545959. The next prime is 1155545983. The reversal of 1155545961 is 1695455511.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1155545961 - 2¹ = 1155545959 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1155545761) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 192590991 + ... + 192590996.

It is an arithmetic number, because the mean of its divisors is an integer number (385181988).

Almost surely, 2^1155545961 is an apocalyptic number.

It is an amenable number.

1155545961 is a deficient number, since it is larger than the sum of its proper divisors (385181991).

1155545961 is an equidigital number, since it uses as much as digits as its factorization.

1155545961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 385181990.

The product of its digits is 135000, while the sum is 42.

The square root of 1155545961 is about 33993.3223001224. The cubic root of 1155545961 is about 1049.3710401024.

The spelling of 1155545961 in words is "one billion, one hundred fifty-five million, five hundred forty-five thousand, nine hundred sixty-one".