20315421 has 32 divisors (see below), whose sum is σ = 35143680. Its totient is φ = 11356848.

The previous prime is 20315413. The next prime is 20315423. The reversal of 20315421 is 12451302.

It is not a de Polignac number, because 20315421 - 2³ = 20315413 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20315394 and 20315403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20315423) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7740 + ... + 10026.

It is an arithmetic number, because the mean of its divisors is an integer number (1098240).

Almost surely, 2^20315421 is an apocalyptic number.

20315421 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20315421 is a deficient number, since it is larger than the sum of its proper divisors (14828259).

20315421 is a wasteful number, since it uses less digits than its factorization.

20315421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2350 (or 2344 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 20315421 is about 4507.2631385354. The cubic root of 20315421 is about 272.8612989430.

Adding to 20315421 its reverse (12451302), we get a palindrome (32766723).

It can be divided in two parts, 20315 and 421, that added together give a 4-th power (20736 = 12⁴).

The spelling of 20315421 in words is "twenty million, three hundred fifteen thousand, four hundred twenty-one".