21456007 has 2 divisors, whose sum is σ = 21456008. Its totient is φ = 21456006.

The previous prime is 21455983. The next prime is 21456047. The reversal of 21456007 is 70065412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21456007 - 2¹⁵ = 21423239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21456047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10728003 + 10728004.

It is an arithmetic number, because the mean of its divisors is an integer number (10728004).

Almost surely, 2^21456007 is an apocalyptic number.

21456007 is a deficient number, since it is larger than the sum of its proper divisors (1).

21456007 is an equidigital number, since it uses as much as digits as its factorization.

21456007 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 21456007 is about 4632.0629313514. The cubic root of 21456007 is about 277.8751013225.

The spelling of 21456007 in words is "twenty-one million, four hundred fifty-six thousand, seven".