21459140 has 12 divisors (see below), whose sum is σ = 45064236. Its totient is φ = 8583648.

The previous prime is 21459133. The next prime is 21459143. The reversal of 21459140 is 4195412.

It can be written as a sum of positive squares in 2 ways, for example, as 13719616 + 7739524 = 3704^2 + 2782^2 .

It is not an unprimeable number, because it can be changed into a prime (21459143) by changing a digit.

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, 536459 + ... + 536498.

It is an arithmetic number, because the mean of its divisors is an integer number (3755353).

Almost surely, 2^21459140 is an apocalyptic number.

21459140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21459140 is an abundant number, since it is smaller than the sum of its proper divisors (23605096).

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

21459140 is a wasteful number, since it uses less digits than its factorization.

21459140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1072966 (or 1072964 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 21459140 is about 4632.4011052585. The cubic root of 21459140 is about 277.8886257451. Note that the first 3 decimals are identical.

The spelling of 21459140 in words is "twenty-one million, four hundred fifty-nine thousand, one hundred forty".