21165340 has 48 divisors (see below), whose sum is σ = 53790912. Its totient is φ = 6829056.

The previous prime is 21165299. The next prime is 21165379. The reversal of 21165340 is 4356112.

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, 2067 + ... + 6826.

It is an arithmetic number, because the mean of its divisors is an integer number (1120644).

Almost surely, 2^21165340 is an apocalyptic number.

21165340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21165340 is an abundant number, since it is smaller than the sum of its proper divisors (32625572).

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

21165340 is a wasteful number, since it uses less digits than its factorization.

21165340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8926 (or 8924 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 21165340 is about 4600.5803981672. The cubic root of 21165340 is about 276.6145899628.

The spelling of 21165340 in words is "twenty-one million, one hundred sixty-five thousand, three hundred forty".