21357043 has 2 divisors, whose sum is σ = 21357044. Its totient is φ = 21357042.

The previous prime is 21357031. The next prime is 21357053. The reversal of 21357043 is 34075312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21357043 - 2¹³ = 21348851 is a prime.

It is a super-3 number, since 3×21357043³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 21356999 and 21357017.

It is not a weakly prime, because it can be changed into another prime (21357053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10678521 + 10678522.

It is an arithmetic number, because the mean of its divisors is an integer number (10678522).

Almost surely, 2^21357043 is an apocalyptic number.

21357043 is a deficient number, since it is larger than the sum of its proper divisors (1).

21357043 is an equidigital number, since it uses as much as digits as its factorization.

21357043 is an evil number, because the sum of its binary digits is even.

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

The square root of 21357043 is about 4621.3680874823. The cubic root of 21357043 is about 277.4472177294.

The spelling of 21357043 in words is "twenty-one million, three hundred fifty-seven thousand, forty-three".