1165531421 has 4 divisors (see below), whose sum is σ = 1226875200. Its totient is φ = 1104187644.

The previous prime is 1165531399. The next prime is 1165531457. The reversal of 1165531421 is 1241355611.

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 1165531421 - 2⁶ = 1165531357 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1165537421) 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, 30671861 + ... + 30671898.

It is an arithmetic number, because the mean of its divisors is an integer number (306718800).

Almost surely, 2^1165531421 is an apocalyptic number.

It is an amenable number.

1165531421 is a deficient number, since it is larger than the sum of its proper divisors (61343779).

1165531421 is an equidigital number, since it uses as much as digits as its factorization.

1165531421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61343778.

The product of its digits is 3600, while the sum is 29.

The square root of 1165531421 is about 34139.8802136153. The cubic root of 1165531421 is about 1052.3850307069.

The spelling of 1165531421 in words is "one billion, one hundred sixty-five million, five hundred thirty-one thousand, four hundred twenty-one".