15500001 has 16 divisors (see below), whose sum is σ = 22821120. Its totient is φ = 9279120.

The previous prime is 15499997. The next prime is 15500011. The reversal of 15500001 is 10000551.

It is not a de Polignac number, because 15500001 - 2² = 15499997 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 15500001.

It is not an unprimeable number, because it can be changed into a prime (15500011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91 + ... + 5568.

It is an arithmetic number, because the mean of its divisors is an integer number (1426320).

Almost surely, 2^15500001 is an apocalyptic number.

15500001 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

15500001 is a deficient number, since it is larger than the sum of its proper divisors (7321119).

15500001 is a wasteful number, since it uses less digits than its factorization.

15500001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5756.

The product of its (nonzero) digits is 25, while the sum is 12.

The square root of 15500001 is about 3937.0040640060. The cubic root of 15500001 is about 249.3315529739.

Adding to 15500001 its reverse (10000551), we get a palindrome (25500552).

The spelling of 15500001 in words is "fifteen million, five hundred thousand, one".