15000020021 has 8 divisors (see below), whose sum is σ = 17303094720. Its totient is φ = 12736999008.

The previous prime is 15000020017. The next prime is 15000020029. The reversal of 15000020021 is 12002000051.

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

It is a cyclic number.

It is not a de Polignac number, because 15000020021 - 2² = 15000020017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 15000019984 and 15000020011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15000020029) 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, 10012616 + ... + 10014113.

It is an arithmetic number, because the mean of its divisors is an integer number (2162886840).

Almost surely, 2^15000020021 is an apocalyptic number.

It is an amenable number.

15000020021 is a deficient number, since it is larger than the sum of its proper divisors (2303074699).

15000020021 is a wasteful number, since it uses less digits than its factorization.

15000020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20026843.

The product of its (nonzero) digits is 20, while the sum is 11.

Adding to 15000020021 its reverse (12002000051), we get a palindrome (27002020072).

The spelling of 15000020021 in words is "fifteen billion, twenty thousand, twenty-one".