21191600 has 60 divisors (see below), whose sum is σ = 52585920. Its totient is φ = 8198400.

The previous prime is 21191591. The next prime is 21191603. The reversal of 21191600 is 619112.

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

It is not an unprimeable number, because it can be changed into a prime (21191603) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11546 + ... + 13254.

It is an arithmetic number, because the mean of its divisors is an integer number (876432).

Almost surely, 2^21191600 is an apocalyptic number.

21191600 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 21191600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26292960).

21191600 is an abundant number, since it is smaller than the sum of its proper divisors (31394320).

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

21191600 is a wasteful number, since it uses less digits than its factorization.

21191600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1758 (or 1747 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 20.

The square root of 21191600 is about 4603.4335012032. The cubic root of 21191600 is about 276.7289419659.

The spelling of 21191600 in words is "twenty-one million, one hundred ninety-one thousand, six hundred".