21576340 has 12 divisors (see below), whose sum is σ = 45310356. Its totient is φ = 8630528.

The previous prime is 21576329. The next prime is 21576367. The reversal of 21576340 is 4367512.

It can be written as a sum of positive squares in 2 ways, for example, as 7333264 + 14243076 = 2708^2 + 3774^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21576299 and 21576308.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 539389 + ... + 539428.

It is an arithmetic number, because the mean of its divisors is an integer number (3775863).

Almost surely, 2^21576340 is an apocalyptic number.

21576340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21576340 is an abundant number, since it is smaller than the sum of its proper divisors (23734016).

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

21576340 is a wasteful number, since it uses less digits than its factorization.

21576340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1078826 (or 1078824 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 21576340 is about 4645.0339073036. The cubic root of 21576340 is about 278.3936076889.

The spelling of 21576340 in words is "twenty-one million, five hundred seventy-six thousand, three hundred forty".