21003479 has 8 divisors (see below), whose sum is σ = 24562560. Its totient is φ = 17584056.

The previous prime is 21003473. The next prime is 21003491. The reversal of 21003479 is 97430012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21003479 - 2⁸ = 21003223 is a prime.

It is a super-2 number, since 2×21003479² = 882292260206882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21003473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34589 + ... + 35190.

It is an arithmetic number, because the mean of its divisors is an integer number (3070320).

Almost surely, 2^21003479 is an apocalyptic number.

21003479 is a deficient number, since it is larger than the sum of its proper divisors (3559081).

21003479 is an equidigital number, since it uses as much as digits as its factorization.

21003479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69829.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 21003479 is about 4582.9552692559. The cubic root of 21003479 is about 275.9076521893.

The spelling of 21003479 in words is "twenty-one million, three thousand, four hundred seventy-nine".