21029085 has 144 divisors (see below), whose sum is σ = 50397120. Its totient is φ = 8225280.

The previous prime is 21029083. The next prime is 21029101. The reversal of 21029085 is 58092012.

21029085 = 69³ + 70³ + ... + 101³.

It is not a de Polignac number, because 21029085 - 2¹ = 21029083 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21029081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1236997 + ... + 1237013.

It is an arithmetic number, because the mean of its divisors is an integer number (349980).

Almost surely, 2^21029085 is an apocalyptic number.

It is an amenable number.

21029085 is an abundant number, since it is smaller than the sum of its proper divisors (29368035).

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

21029085 is a wasteful number, since it uses less digits than its factorization.

21029085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73 (or 43 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 21029085 is about 4585.7480305835. The cubic root of 21029085 is about 276.0197292135.

The spelling of 21029085 in words is "twenty-one million, twenty-nine thousand, eighty-five".