21494879 has 6 divisors (see below), whose sum is σ = 25004304. Its totient is φ = 18424140.

The previous prime is 21494861. The next prime is 21494881. The reversal of 21494879 is 97849412.

It is not a de Polignac number, because 21494879 - 2¹² = 21490783 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 (21494849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 219287 + ... + 219384.

It is an arithmetic number, because the mean of its divisors is an integer number (4167384).

Almost surely, 2^21494879 is an apocalyptic number.

21494879 is a deficient number, since it is larger than the sum of its proper divisors (3509425).

21494879 is an equidigital number, since it uses as much as digits as its factorization.

21494879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 438685 (or 438678 counting only the distinct ones).

The product of its digits is 145152, while the sum is 44.

The square root of 21494879 is about 4636.2570032301. The cubic root of 21494879 is about 278.0428095142.

The spelling of 21494879 in words is "twenty-one million, four hundred ninety-four thousand, eight hundred seventy-nine".