21147400 has 48 divisors (see below), whose sum is σ = 50331600. Its totient is φ = 8258880.

The previous prime is 21147397. The next prime is 21147433. The reversal of 21147400 is 474112.

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, 7371 + ... + 9829.

It is an arithmetic number, because the mean of its divisors is an integer number (1048575).

Almost surely, 2^21147400 is an apocalyptic number.

21147400 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 21147400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25165800).

21147400 is an abundant number, since it is smaller than the sum of its proper divisors (29184200).

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

21147400 is a wasteful number, since it uses less digits than its factorization.

21147400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2518 (or 2509 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 19.

The square root of 21147400 is about 4598.6302308405. The cubic root of 21147400 is about 276.5364139057.

The spelling of 21147400 in words is "twenty-one million, one hundred forty-seven thousand, four hundred".