20521313 has 8 divisors (see below), whose sum is σ = 21553728. Its totient is φ = 19500624.

The previous prime is 20521309. The next prime is 20521331. The reversal of 20521313 is 31312502.

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 20521313 - 2² = 20521309 is a prime.

It is a super-2 number, since 2×20521313² = 842248574487938, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20521291 and 20521300.

It is not an unprimeable number, because it can be changed into a prime (20521373) 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, 770 + ... + 6452.

It is an arithmetic number, because the mean of its divisors is an integer number (2694216).

Almost surely, 2^20521313 is an apocalyptic number.

20521313 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

20521313 is a deficient number, since it is larger than the sum of its proper divisors (1032415).

20521313 is a wasteful number, since it uses less digits than its factorization.

20521313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5863.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 20521313 is about 4530.0455847596. The cubic root of 20521313 is about 273.7799972688.

Adding to 20521313 its reverse (31312502), we get a palindrome (51833815).

The spelling of 20521313 in words is "twenty million, five hundred twenty-one thousand, three hundred thirteen".