21829477 has 2 divisors, whose sum is σ = 21829478. Its totient is φ = 21829476.

The previous prime is 21829463. The next prime is 21829501. The reversal of 21829477 is 77492812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21818241 + 11236 = 4671^2 + 106^2 .

It is a cyclic number.

It is not a de Polignac number, because 21829477 - 2⁷ = 21829349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21829777) 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 as a sum of consecutive naturals, namely, 10914738 + 10914739.

It is an arithmetic number, because the mean of its divisors is an integer number (10914739).

Almost surely, 2^21829477 is an apocalyptic number.

It is an amenable number.

21829477 is a deficient number, since it is larger than the sum of its proper divisors (1).

21829477 is an equidigital number, since it uses as much as digits as its factorization.

21829477 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56448, while the sum is 40.

The square root of 21829477 is about 4672.2025855050. The cubic root of 21829477 is about 279.4780966853.

The spelling of 21829477 in words is "twenty-one million, eight hundred twenty-nine thousand, four hundred seventy-seven".