21057343 has 4 divisors (see below), whose sum is σ = 21096808. Its totient is φ = 21017880.

The previous prime is 21057341. The next prime is 21057419. The reversal of 21057343 is 34375012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21057343 - 2¹ = 21057341 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21057341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18921 + ... + 20002.

It is an arithmetic number, because the mean of its divisors is an integer number (5274202).

Almost surely, 2^21057343 is an apocalyptic number.

21057343 is a deficient number, since it is larger than the sum of its proper divisors (39465).

21057343 is an equidigital number, since it uses as much as digits as its factorization.

21057343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39464.

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 21057343 is about 4588.8280638961. The cubic root of 21057343 is about 276.1433084443.

The spelling of 21057343 in words is "twenty-one million, fifty-seven thousand, three hundred forty-three".