21361420 has 24 divisors (see below), whose sum is σ = 45151344. Its totient is φ = 8488896.

The previous prime is 21361397. The next prime is 21361421. The reversal of 21361420 is 2416312.

It is not an unprimeable number, because it can be changed into a prime (21361421) 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, 262 + ... + 6541.

It is an arithmetic number, because the mean of its divisors is an integer number (1881306).

Almost surely, 2^21361420 is an apocalyptic number.

21361420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21361420 is an abundant number, since it is smaller than the sum of its proper divisors (23789924).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21361420 is a wasteful number, since it uses less digits than its factorization.

21361420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6969 (or 6967 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 21361420 is about 4621.8416242879. The cubic root of 21361420 is about 277.4661701584.

Adding to 21361420 its reverse (2416312), we get a palindrome (23777732).

The spelling of 21361420 in words is "twenty-one million, three hundred sixty-one thousand, four hundred twenty".