1091005421 has 16 divisors (see below), whose sum is σ = 1240630080. Its totient is φ = 950590080.

The previous prime is 1091005393. The next prime is 1091005427. The reversal of 1091005421 is 1245001901.

It is a happy number.

It is not a de Polignac number, because 1091005421 - 2¹⁴ = 1090989037 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091005427) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7265 + ... + 47273.

It is an arithmetic number, because the mean of its divisors is an integer number (77539380).

Almost surely, 2^1091005421 is an apocalyptic number.

1091005421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1091005421 is a deficient number, since it is larger than the sum of its proper divisors (149624659).

1091005421 is a wasteful number, since it uses less digits than its factorization.

1091005421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40124.

The product of its (nonzero) digits is 360, while the sum is 23.

The square root of 1091005421 is about 33030.3711907693. The cubic root of 1091005421 is about 1029.4587979069.

The spelling of 1091005421 in words is "one billion, ninety-one million, five thousand, four hundred twenty-one".