21267500 has 60 divisors (see below), whose sum is σ = 47759712. Its totient is φ = 8280000.

The previous prime is 21267497. The next prime is 21267503. The reversal of 21267500 is 576212.

It is an interprime number because it is at equal distance from previous prime (21267497) and next prime (21267503).

It is not an unprimeable number, because it can be changed into a prime (21267503) 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, 117410 + ... + 117590.

Almost surely, 2^21267500 is an apocalyptic number.

21267500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21267500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23879856).

21267500 is an abundant number, since it is smaller than the sum of its proper divisors (26492212).

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

21267500 is a wasteful number, since it uses less digits than its factorization.

21267500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252 (or 235 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 21267500 is about 4611.6699795193. The cubic root of 21267500 is about 277.0589265001.

The spelling of 21267500 in words is "twenty-one million, two hundred sixty-seven thousand, five hundred".