21116940 has 48 divisors (see below), whose sum is σ = 63678048. Its totient is φ = 5197824.

The previous prime is 21116933. The next prime is 21116951. The reversal of 21116940 is 4961112.

It is a self number, because there is not a number n which added to its sum of digits gives 21116940.

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, 12757 + ... + 14316.

It is an arithmetic number, because the mean of its divisors is an integer number (1326626).

Almost surely, 2^21116940 is an apocalyptic number.

21116940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21116940 is an abundant number, since it is smaller than the sum of its proper divisors (42561108).

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

21116940 is a wasteful number, since it uses less digits than its factorization.

21116940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27098 (or 27096 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 21116940 is about 4595.3171816535. The cubic root of 21116940 is about 276.4035788744.

The spelling of 21116940 in words is "twenty-one million, one hundred sixteen thousand, nine hundred forty".