21452407 has 2 divisors, whose sum is σ = 21452408. Its totient is φ = 21452406.

The previous prime is 21452393. The next prime is 21452411. The reversal of 21452407 is 70425412.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21452407 is a prime.

It is a plaindrome in base 11.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21452467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10726203 + 10726204.

It is an arithmetic number, because the mean of its divisors is an integer number (10726204).

Almost surely, 2^21452407 is an apocalyptic number.

21452407 is a deficient number, since it is larger than the sum of its proper divisors (1).

21452407 is an equidigital number, since it uses as much as digits as its factorization.

21452407 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2240, while the sum is 25.

The square root of 21452407 is about 4631.6743192932. The cubic root of 21452407 is about 277.8595593452.

Adding to 21452407 its reverse (70425412), we get a palindrome (91877819).

The spelling of 21452407 in words is "twenty-one million, four hundred fifty-two thousand, four hundred seven".