21996140 has 12 divisors (see below), whose sum is σ = 46191936. Its totient is φ = 8798448.

The previous prime is 21996127. The next prime is 21996151. The reversal of 21996140 is 4169912.

It is a junction number, because it is equal to n+sod(n) for n = 21996097 and 21996106.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 549884 + ... + 549923.

It is an arithmetic number, because the mean of its divisors is an integer number (3849328).

Almost surely, 2^21996140 is an apocalyptic number.

21996140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21996140 is an abundant number, since it is smaller than the sum of its proper divisors (24195796).

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

21996140 is a wasteful number, since it uses less digits than its factorization.

21996140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1099816 (or 1099814 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 21996140 is about 4690.0042643904. The cubic root of 21996140 is about 280.1875444224.

The spelling of 21996140 in words is "twenty-one million, nine hundred ninety-six thousand, one hundred forty".