20999755 has 8 divisors (see below), whose sum is σ = 28799712. Its totient is φ = 14399808.

The previous prime is 20999729. The next prime is 20999767. The reversal of 20999755 is 55799902.

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

It is a cyclic number.

It is not a de Polignac number, because 20999755 - 2⁵ = 20999723 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 299962 + ... + 300031.

It is an arithmetic number, because the mean of its divisors is an integer number (3599964).

Almost surely, 2^20999755 is an apocalyptic number.

20999755 is a deficient number, since it is larger than the sum of its proper divisors (7799957).

20999755 is an equidigital number, since it uses as much as digits as its factorization.

20999755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 600005.

The product of its (nonzero) digits is 255150, while the sum is 46.

The square root of 20999755 is about 4582.5489631863. The cubic root of 20999755 is about 275.8913447190.

The spelling of 20999755 in words is "twenty million, nine hundred ninety-nine thousand, seven hundred fifty-five".