21304426 has 32 divisors (see below), whose sum is σ = 37856448. Its totient is φ = 8864640.

The previous prime is 21304397. The next prime is 21304427. The reversal of 21304426 is 62440312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 21304397 and 21304406.

It is not an unprimeable number, because it can be changed into a prime (21304427) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46390 + ... + 46846.

It is an arithmetic number, because the mean of its divisors is an integer number (1183014).

Almost surely, 2^21304426 is an apocalyptic number.

21304426 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21304426 is a deficient number, since it is larger than the sum of its proper divisors (16552022).

21304426 is a wasteful number, since it uses less digits than its factorization.

21304426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 21304426 is about 4615.6717820920. The cubic root of 21304426 is about 277.2191829567.

Adding to 21304426 its reverse (62440312), we get a palindrome (83744738).

It can be divided in two parts, 2130 and 4426, that added together give a palindrome (6556).

The spelling of 21304426 in words is "twenty-one million, three hundred four thousand, four hundred twenty-six".