21457350 has 72 divisors (see below), whose sum is σ = 59105592. Its totient is φ = 5577600.

The previous prime is 21457339. The next prime is 21457379. The reversal of 21457350 is 5375412.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 17869 + ... + 19031.

It is an arithmetic number, because the mean of its divisors is an integer number (820911).

Almost surely, 2^21457350 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21457350, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29552796).

21457350 is an abundant number, since it is smaller than the sum of its proper divisors (37648242).

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

21457350 is a wasteful number, since it uses less digits than its factorization.

21457350 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1222 (or 1214 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 27.

The square root of 21457350 is about 4632.2078968889. The cubic root of 21457350 is about 277.8808988982.

The spelling of 21457350 in words is "twenty-one million, four hundred fifty-seven thousand, three hundred fifty".