21703140 has 60 divisors (see below), whose sum is σ = 68088636. Its totient is φ = 5787072.

The previous prime is 21703133. The next prime is 21703141. The reversal of 21703140 is 4130712.

It can be written as a sum of positive squares in 2 ways, for example, as 3504384 + 18198756 = 1872^2 + 4266^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21703141) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 5079 + ... + 8318.

Almost surely, 2^21703140 is an apocalyptic number.

21703140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21703140 is an abundant number, since it is smaller than the sum of its proper divisors (46385496).

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

21703140 is a wasteful number, since it uses less digits than its factorization.

21703140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13418 (or 13407 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 21703140 is about 4658.6628983003. The cubic root of 21703140 is about 278.9378980752.

Adding to 21703140 its reverse (4130712), we get a palindrome (25833852).

The spelling of 21703140 in words is "twenty-one million, seven hundred three thousand, one hundred forty".