21271700 has 36 divisors (see below), whose sum is σ = 46385052. Its totient is φ = 8467200.

The previous prime is 21271699. The next prime is 21271721. The reversal of 21271700 is 717212.

It can be written as a sum of positive squares in 6 ways, for example, as 1156 + 21270544 = 34^2 + 4612^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27722 + ... + 28478.

Almost surely, 2^21271700 is an apocalyptic number.

21271700 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21271700 is an abundant number, since it is smaller than the sum of its proper divisors (25113352).

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

21271700 is a wasteful number, since it uses less digits than its factorization.

21271700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1052 (or 1045 counting only the distinct ones).

The product of its (nonzero) digits is 196, while the sum is 20.

The square root of 21271700 is about 4612.1253235358. The cubic root of 21271700 is about 277.0771635739.

Adding to 21271700 its reverse (717212), we get a palindrome (21988912).

The spelling of 21271700 in words is "twenty-one million, two hundred seventy-one thousand, seven hundred".