21450079 has 4 divisors (see below), whose sum is σ = 24514384. Its totient is φ = 18385776.

The previous prime is 21450061. The next prime is 21450083. The reversal of 21450079 is 97005412.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21450079 - 2¹³ = 21441887 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21450019) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1532142 + ... + 1532155.

It is an arithmetic number, because the mean of its divisors is an integer number (6128596).

Almost surely, 2^21450079 is an apocalyptic number.

21450079 is a deficient number, since it is larger than the sum of its proper divisors (3064305).

21450079 is an equidigital number, since it uses as much as digits as its factorization.

21450079 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3064304.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 21450079 is about 4631.4229994679. The cubic root of 21450079 is about 277.8495079408.

The spelling of 21450079 in words is "twenty-one million, four hundred fifty thousand, seventy-nine".