21776140 has 12 divisors (see below), whose sum is σ = 45729936. Its totient is φ = 8710448.

The previous prime is 21776123. The next prime is 21776141. The reversal of 21776140 is 4167712.

It is a junction number, because it is equal to n+sod(n) for n = 21776099 and 21776108.

It is not an unprimeable number, because it can be changed into a prime (21776141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 544384 + ... + 544423.

It is an arithmetic number, because the mean of its divisors is an integer number (3810828).

Almost surely, 2^21776140 is an apocalyptic number.

21776140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21776140 is an abundant number, since it is smaller than the sum of its proper divisors (23953796).

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

21776140 is a wasteful number, since it uses less digits than its factorization.

21776140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1088816 (or 1088814 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 21776140 is about 4666.4911871769. The cubic root of 21776140 is about 279.2502903365.

It can be divided in two parts, 21 and 776140, that added together give a square (776161 = 881²).

The spelling of 21776140 in words is "twenty-one million, seven hundred seventy-six thousand, one hundred forty".