1540021001 has 4 divisors (see below), whose sum is σ = 1547760000. Its totient is φ = 1532282004.

The previous prime is 1540020991. The next prime is 1540021013. The reversal of 1540021001 is 1001200451.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1001200451 = 569 ⋅1759579.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1540021001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1540021081) 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 3 ways as a sum of consecutive naturals, for example, 3869201 + ... + 3869598.

It is an arithmetic number, because the mean of its divisors is an integer number (386940000).

Almost surely, 2^1540021001 is an apocalyptic number.

It is an amenable number.

1540021001 is a deficient number, since it is larger than the sum of its proper divisors (7738999).

1540021001 is an equidigital number, since it uses as much as digits as its factorization.

1540021001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7738998.

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 1540021001 is about 39243.1013173016. The cubic root of 1540021001 is about 1154.8055996101.

Adding to 1540021001 its reverse (1001200451), we get a palindrome (2541221452).

The spelling of 1540021001 in words is "one billion, five hundred forty million, twenty-one thousand, one".