21019479 has 16 divisors (see below), whose sum is σ = 30610944. Its totient is φ = 12751200.

The previous prime is 21019459. The next prime is 21019487. The reversal of 21019479 is 97491012.

It is not a de Polignac number, because 21019479 - 2⁹ = 21018967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21019409) 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 15 ways as a sum of consecutive naturals, for example, 1027 + ... + 6564.

It is an arithmetic number, because the mean of its divisors is an integer number (1913184).

Almost surely, 2^21019479 is an apocalyptic number.

21019479 is a deficient number, since it is larger than the sum of its proper divisors (9591465).

21019479 is a wasteful number, since it uses less digits than its factorization.

21019479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7678.

The product of its (nonzero) digits is 4536, while the sum is 33.

The square root of 21019479 is about 4584.7005354767. The cubic root of 21019479 is about 275.9776945847.

The spelling of 21019479 in words is "twenty-one million, nineteen thousand, four hundred seventy-nine".