21059514 has 80 divisors (see below), whose sum is σ = 55176000. Its totient is φ = 6001128.

The previous prime is 21059477. The next prime is 21059537. The reversal of 21059514 is 41595012.

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

It is a congruent number.

It is an unprimeable number.

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 in 39 ways as a sum of consecutive naturals, for example, 55377 + ... + 55755.

It is an arithmetic number, because the mean of its divisors is an integer number (689700).

Almost surely, 2^21059514 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21059514, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27588000).

21059514 is an abundant number, since it is smaller than the sum of its proper divisors (34116486).

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

21059514 is an equidigital number, since it uses as much as digits as its factorization.

21059514 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 414 (or 391 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 21059514 is about 4589.0646105715. The cubic root of 21059514 is about 276.1527981905.

The spelling of 21059514 in words is "twenty-one million, fifty-nine thousand, five hundred fourteen".