21829501 has 2 divisors, whose sum is σ = 21829502. Its totient is φ = 21829500.

The previous prime is 21829477. The next prime is 21829529. The reversal of 21829501 is 10592812.

It is an a-pointer prime, because the next prime (21829529) can be obtained adding 21829501 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18714276 + 3115225 = 4326^2 + 1765^2 .

It is a cyclic number.

It is not a de Polignac number, because 21829501 - 2¹¹ = 21827453 is a prime.

It is a super-2 number, since 2×21829501² = 953054227818002, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21829501.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21229501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10914750 + 10914751.

It is an arithmetic number, because the mean of its divisors is an integer number (10914751).

Almost surely, 2^21829501 is an apocalyptic number.

It is an amenable number.

21829501 is a deficient number, since it is larger than the sum of its proper divisors (1).

21829501 is an equidigital number, since it uses as much as digits as its factorization.

21829501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 21829501 is about 4672.2051538861. The cubic root of 21829501 is about 279.4781991075.

The spelling of 21829501 in words is "twenty-one million, eight hundred twenty-nine thousand, five hundred one".