21359047 has 2 divisors, whose sum is σ = 21359048. Its totient is φ = 21359046.

The previous prime is 21359017. The next prime is 21359057. The reversal of 21359047 is 74095312.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21359047 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21359017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10679523 + 10679524.

It is an arithmetic number, because the mean of its divisors is an integer number (10679524).

Almost surely, 2^21359047 is an apocalyptic number.

21359047 is a deficient number, since it is larger than the sum of its proper divisors (1).

21359047 is an equidigital number, since it uses as much as digits as its factorization.

21359047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 21359047 is about 4621.5849013082. The cubic root of 21359047 is about 277.4558953795.

The spelling of 21359047 in words is "twenty-one million, three hundred fifty-nine thousand, forty-seven".