15540000001 has 4 divisors (see below), whose sum is σ = 16075862100. Its totient is φ = 15004137904.

The previous prime is 15539999987. The next prime is 15540000011. The reversal of 15540000001 is 10000004551.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10000004551 = 19 ⋅526316029.

It can be written as a sum of positive squares in 2 ways, for example, as 12395482225 + 3144517776 = 111335^2 + 56076^2 .

It is a cyclic number.

It is not a de Polignac number, because 15540000001 - 2⁷ = 15539999873 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 15540000001.

It is not an unprimeable number, because it can be changed into a prime (15540000011) 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, 267931006 + ... + 267931063.

It is an arithmetic number, because the mean of its divisors is an integer number (4018965525).

Almost surely, 2^15540000001 is an apocalyptic number.

It is an amenable number.

15540000001 is a deficient number, since it is larger than the sum of its proper divisors (535862099).

15540000001 is an equidigital number, since it uses as much as digits as its factorization.

15540000001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 535862098.

The product of its (nonzero) digits is 100, while the sum is 16.

Adding to 15540000001 its reverse (10000004551), we get a palindrome (25540004552).

The spelling of 15540000001 in words is "fifteen billion, five hundred forty million, one", and thus it is an aban number.