21059799 has 8 divisors (see below), whose sum is σ = 28129920. Its totient is φ = 14014776.

The previous prime is 21059791. The next prime is 21059827. The reversal of 21059799 is 99795012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21059799 - 2³ = 21059791 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21059799.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21059791) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4219 + ... + 7740.

It is an arithmetic number, because the mean of its divisors is an integer number (3516240).

Almost surely, 2^21059799 is an apocalyptic number.

21059799 is a deficient number, since it is larger than the sum of its proper divisors (7070121).

21059799 is a wasteful number, since it uses less digits than its factorization.

21059799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12549.

The product of its (nonzero) digits is 51030, while the sum is 42.

The square root of 21059799 is about 4589.0956625462. The cubic root of 21059799 is about 276.1540439171.

The spelling of 21059799 in words is "twenty-one million, fifty-nine thousand, seven hundred ninety-nine".