21259420 has 48 divisors (see below), whose sum is σ = 54952128. Its totient is φ = 6727680.

The previous prime is 21259417. The next prime is 21259439. The reversal of 21259420 is 2495212.

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, 4021 + ... + 7660.

It is an arithmetic number, because the mean of its divisors is an integer number (1144836).

Almost surely, 2^21259420 is an apocalyptic number.

21259420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21259420 is an abundant number, since it is smaller than the sum of its proper divisors (33692708).

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

21259420 is a wasteful number, since it uses less digits than its factorization.

21259420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11710 (or 11708 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 21259420 is about 4610.7938578948. The cubic root of 21259420 is about 277.0238350901.

The spelling of 21259420 in words is "twenty-one million, two hundred fifty-nine thousand, four hundred twenty".