315200021 has 4 divisors (see below), whose sum is σ = 315250944. Its totient is φ = 315149100.

The previous prime is 315199979. The next prime is 315200047. The reversal of 315200021 is 120002513.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 315200021 - 2¹⁰ = 315198997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 315199969 and 315200005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (315200051) 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, 14645 + ... + 29066.

It is an arithmetic number, because the mean of its divisors is an integer number (78812736).

Almost surely, 2^315200021 is an apocalyptic number.

It is an amenable number.

315200021 is a deficient number, since it is larger than the sum of its proper divisors (50923).

315200021 is an equidigital number, since it uses as much as digits as its factorization.

315200021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50922.

The product of its (nonzero) digits is 60, while the sum is 14.

The square root of 315200021 is about 17753.8734083580. The cubic root of 315200021 is about 680.5531981928.

Adding to 315200021 its reverse (120002513), we get a palindrome (435202534).

The spelling of 315200021 in words is "three hundred fifteen million, two hundred thousand, twenty-one".