21504002001 has 8 divisors (see below), whose sum is σ = 30181055520. Its totient is φ = 13581474912.

The previous prime is 21504001969. The next prime is 21504002027. The reversal of 21504002001 is 10020040512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21504002001 - 2⁵ = 21504001969 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21504002041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 188631540 + ... + 188631653.

It is an arithmetic number, because the mean of its divisors is an integer number (3772631940).

Almost surely, 2^21504002001 is an apocalyptic number.

It is an amenable number.

21504002001 is a deficient number, since it is larger than the sum of its proper divisors (8677053519).

21504002001 is a wasteful number, since it uses less digits than its factorization.

21504002001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 377263215.

The product of its (nonzero) digits is 80, while the sum is 15.

Adding to 21504002001 its reverse (10020040512), we get a palindrome (31524042513).

The spelling of 21504002001 in words is "twenty-one billion, five hundred four million, two thousand, one".