21634800 has 180 divisors, whose sum is σ = 76687800. Its totient is φ = 5209600.

The previous prime is 21634799. The next prime is 21634801. The reversal of 21634800 is 843612.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21634799) and next prime (21634801).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21634801) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 145126 + ... + 145274.

Almost surely, 2^21634800 is an apocalyptic number.

21634800 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 21634800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38343900).

21634800 is an abundant number, since it is smaller than the sum of its proper divisors (55053000).

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

21634800 is a wasteful number, since it uses less digits than its factorization.

21634800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192 (or 170 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 21634800 is about 4651.3223926105. The cubic root of 21634800 is about 278.6448120749.

The spelling of 21634800 in words is "twenty-one million, six hundred thirty-four thousand, eight hundred".