21326340 has 48 divisors (see below), whose sum is σ = 68245632. Its totient is φ = 4874496.

The previous prime is 21326309. The next prime is 21326351. The reversal of 21326340 is 4362312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24969 + ... + 25808.

It is an arithmetic number, because the mean of its divisors is an integer number (1421784).

Almost surely, 2^21326340 is an apocalyptic number.

21326340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21326340 is an abundant number, since it is smaller than the sum of its proper divisors (46919292).

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

21326340 is a wasteful number, since it uses less digits than its factorization.

21326340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50796 (or 50794 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 21.

The square root of 21326340 is about 4618.0450409237. The cubic root of 21326340 is about 277.3142007624.

Adding to 21326340 its reverse (4362312), we get a palindrome (25688652).

The spelling of 21326340 in words is "twenty-one million, three hundred twenty-six thousand, three hundred forty".