21029859 has 12 divisors (see below), whose sum is σ = 30536376. Its totient is φ = 13946112.

The previous prime is 21029857. The next prime is 21029951. The reversal of 21029859 is 95892012.

It is not a de Polignac number, because 21029859 - 2¹ = 21029857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21029857) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4317 + ... + 7790.

It is an arithmetic number, because the mean of its divisors is an integer number (2544698).

Almost surely, 2^21029859 is an apocalyptic number.

21029859 is a deficient number, since it is larger than the sum of its proper divisors (9506517).

21029859 is a wasteful number, since it uses less digits than its factorization.

21029859 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12306 (or 12303 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 21029859 is about 4585.8324217093. The cubic root of 21029859 is about 276.0231155813.

The spelling of 21029859 in words is "twenty-one million, twenty-nine thousand, eight hundred fifty-nine".