21454039 has 2 divisors, whose sum is σ = 21454040. Its totient is φ = 21454038.

The previous prime is 21454019. The next prime is 21454049. The reversal of 21454039 is 93045412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21454039 - 2⁵ = 21454007 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21453998 and 21454016.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21454019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10727019 + 10727020.

It is an arithmetic number, because the mean of its divisors is an integer number (10727020).

Almost surely, 2^21454039 is an apocalyptic number.

21454039 is a deficient number, since it is larger than the sum of its proper divisors (1).

21454039 is an equidigital number, since it uses as much as digits as its factorization.

21454039 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 21454039 is about 4631.8504941330. The cubic root of 21454039 is about 277.8666052570.

It can be divided in two parts, 2145403 and 9, that added together give a palindrome (2145412).

The spelling of 21454039 in words is "twenty-one million, four hundred fifty-four thousand, thirty-nine".