21579036 has 12 divisors (see below), whose sum is σ = 50351112. Its totient is φ = 7193008.

The previous prime is 21579031. The next prime is 21579043. The reversal of 21579036 is 63097512.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 21578988 and 21579006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21579031) 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, 899115 + ... + 899138.

It is an arithmetic number, because the mean of its divisors is an integer number (4195926).

Almost surely, 2^21579036 is an apocalyptic number.

It is an amenable number.

21579036 is an abundant number, since it is smaller than the sum of its proper divisors (28772076).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21579036 is a wasteful number, since it uses less digits than its factorization.

21579036 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1798260 (or 1798258 counting only the distinct ones).

The product of its (nonzero) digits is 11340, while the sum is 33.

The square root of 21579036 is about 4645.3241006414. The cubic root of 21579036 is about 278.4052024560.

The spelling of 21579036 in words is "twenty-one million, five hundred seventy-nine thousand, thirty-six".