21283140 has 48 divisors (see below), whose sum is σ = 61209792. Its totient is φ = 5521536.

The previous prime is 21283139. The next prime is 21283147. The reversal of 21283140 is 4138212.

It is not an unprimeable number, because it can be changed into a prime (21283147) 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, 2574 + ... + 7013.

It is an arithmetic number, because the mean of its divisors is an integer number (1275204).

Almost surely, 2^21283140 is an apocalyptic number.

21283140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21283140 is an abundant number, since it is smaller than the sum of its proper divisors (39926652).

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

21283140 is a wasteful number, since it uses less digits than its factorization.

21283140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9636 (or 9634 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 21283140 is about 4613.3653659774. The cubic root of 21283140 is about 277.1268257179.

The spelling of 21283140 in words is "twenty-one million, two hundred eighty-three thousand, one hundred forty".