21430767 has 4 divisors (see below), whose sum is σ = 28574360. Its totient is φ = 14287176.

The previous prime is 21430757. The next prime is 21430769. The reversal of 21430767 is 76703412.

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

It is not a de Polignac number, because 21430767 - 2⁷ = 21430639 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21430769) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3571792 + ... + 3571797.

It is an arithmetic number, because the mean of its divisors is an integer number (7143590).

Almost surely, 2^21430767 is an apocalyptic number.

21430767 is a deficient number, since it is larger than the sum of its proper divisors (7143593).

21430767 is an equidigital number, since it uses as much as digits as its factorization.

21430767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7143592.

The product of its (nonzero) digits is 7056, while the sum is 30.

The square root of 21430767 is about 4629.3376416071. The cubic root of 21430767 is about 277.7660981341.

The spelling of 21430767 in words is "twenty-one million, four hundred thirty thousand, seven hundred sixty-seven".