21095380 has 12 divisors (see below), whose sum is σ = 44300340. Its totient is φ = 8438144.

The previous prime is 21095357. The next prime is 21095381. The reversal of 21095380 is 8359012.

It can be written as a sum of positive squares in 2 ways, for example, as 13675204 + 7420176 = 3698^2 + 2724^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21095381) 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, 527365 + ... + 527404.

It is an arithmetic number, because the mean of its divisors is an integer number (3691695).

Almost surely, 2^21095380 is an apocalyptic number.

21095380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21095380 is an abundant number, since it is smaller than the sum of its proper divisors (23204960).

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

21095380 is a wasteful number, since it uses less digits than its factorization.

21095380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1054778 (or 1054776 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 21095380 is about 4592.9707162141. The cubic root of 21095380 is about 276.3094792178.

The spelling of 21095380 in words is "twenty-one million, ninety-five thousand, three hundred eighty".