21434587 has 2 divisors, whose sum is σ = 21434588. Its totient is φ = 21434586.

The previous prime is 21434579. The next prime is 21434591. The reversal of 21434587 is 78543412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21434587 - 2³ = 21434579 is a prime.

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

It is not a weakly prime, because it can be changed into another prime (21444587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10717293 + 10717294.

It is an arithmetic number, because the mean of its divisors is an integer number (10717294).

Almost surely, 2^21434587 is an apocalyptic number.

21434587 is a deficient number, since it is larger than the sum of its proper divisors (1).

21434587 is an equidigital number, since it uses as much as digits as its factorization.

21434587 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26880, while the sum is 34.

The square root of 21434587 is about 4629.7502092446. The cubic root of 21434587 is about 277.7826009414.

Adding to 21434587 its reverse (78543412), we get a palindrome (99977999).

The spelling of 21434587 in words is "twenty-one million, four hundred thirty-four thousand, five hundred eighty-seven".