1053440721 has 36 divisors (see below), whose sum is σ = 1588258672. Its totient is φ = 698667768.

The previous prime is 1053440711. The next prime is 1053440723. The reversal of 1053440721 is 1270443501.

It is not a de Polignac number, because 1053440721 - 2¹⁹ = 1052916433 is a prime.

It is a super-2 number, since 2×1053440721² = 2219474705321999682, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1053440723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2013966 + ... + 2014488.

Almost surely, 2^1053440721 is an apocalyptic number.

It is an amenable number.

1053440721 is a deficient number, since it is larger than the sum of its proper divisors (534817951).

1053440721 is an frugal number, since it uses more digits than its factorization.

1053440721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 854 (or 833 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 1053440721 is about 32456.7515472513. The cubic root of 1053440721 is about 1017.5053483491.

The spelling of 1053440721 in words is "one billion, fifty-three million, four hundred forty thousand, seven hundred twenty-one".