21829500 has 360 divisors, whose sum is σ = 90378288. Its totient is φ = 4536000.

The previous prime is 21829477. The next prime is 21829501. The reversal of 21829500 is 592812.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21829501) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 1984495 + ... + 1984505.

Almost surely, 2^21829500 is an apocalyptic number.

21829500 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 21829500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45189144).

21829500 is an abundant number, since it is smaller than the sum of its proper divisors (68548788).

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

21829500 is a wasteful number, since it uses less digits than its factorization.

21829500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56 (or 28 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 21829500 is about 4672.2050468703. The cubic root of 21829500 is about 279.4781948399.

The spelling of 21829500 in words is "twenty-one million, eight hundred twenty-nine thousand, five hundred".