21257334 has 48 divisors (see below), whose sum is σ = 53138592. Its totient is φ = 6015744.

The previous prime is 21257323. The next prime is 21257347. The reversal of 21257334 is 43375212.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21257298 and 21257307.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13492 + ... + 14984.

It is an arithmetic number, because the mean of its divisors is an integer number (1107054).

Almost surely, 2^21257334 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21257334, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26569296).

21257334 is an abundant number, since it is smaller than the sum of its proper divisors (31881258).

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

21257334 is a wasteful number, since it uses less digits than its factorization.

21257334 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1621 (or 1618 counting only the distinct ones).

The product of its digits is 5040, while the sum is 27.

The square root of 21257334 is about 4610.5676440109. The cubic root of 21257334 is about 277.0147741558.

The spelling of 21257334 in words is "twenty-one million, two hundred fifty-seven thousand, three hundred thirty-four".