1405140521 has 4 divisors (see below), whose sum is σ = 1412273412. Its totient is φ = 1398007632.

The previous prime is 1405140461. The next prime is 1405140533. The reversal of 1405140521 is 1250415041.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 693584896 + 711555625 = 26336^2 + 26675^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1405140521 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1405140721) 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, 3566150 + ... + 3566543.

It is an arithmetic number, because the mean of its divisors is an integer number (353068353).

Almost surely, 2^1405140521 is an apocalyptic number.

It is an amenable number.

1405140521 is a deficient number, since it is larger than the sum of its proper divisors (7132891).

1405140521 is an equidigital number, since it uses as much as digits as its factorization.

1405140521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7132890.

The product of its (nonzero) digits is 800, while the sum is 23.

The square root of 1405140521 is about 37485.2040277227. The cubic root of 1405140521 is about 1120.0564706327.

Adding to 1405140521 its reverse (1250415041), we get a palindrome (2655555562).

The spelling of 1405140521 in words is "one billion, four hundred five million, one hundred forty thousand, five hundred twenty-one".