21579049 has 2 divisors, whose sum is σ = 21579050. Its totient is φ = 21579048.

The previous prime is 21579043. The next prime is 21579053. The reversal of 21579049 is 94097512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17139600 + 4439449 = 4140^2 + 2107^2 .

It is a cyclic number.

It is not a de Polignac number, because 21579049 - 2⁵ = 21579017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21578999 and 21579017.

It is not a weakly prime, because it can be changed into another prime (21579043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10789524 + 10789525.

It is an arithmetic number, because the mean of its divisors is an integer number (10789525).

Almost surely, 2^21579049 is an apocalyptic number.

It is an amenable number.

21579049 is a deficient number, since it is larger than the sum of its proper divisors (1).

21579049 is an equidigital number, since it uses as much as digits as its factorization.

21579049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 21579049 is about 4645.3254998977. The cubic root of 21579049 is about 278.4052583631.

The spelling of 21579049 in words is "twenty-one million, five hundred seventy-nine thousand, forty-nine".