20629985 has 8 divisors (see below), whose sum is σ = 25223400. Its totient is φ = 16192384.

The previous prime is 20629969. The next prime is 20629997. The reversal of 20629985 is 58992602.

It can be written as a sum of positive squares in 4 ways, for example, as 1164241 + 19465744 = 1079^2 + 4412^2 .

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 20629985 - 2⁴ = 20629969 is a prime.

It is a super-2 number, since 2×20629985² = 851192562200450, which contains 22 as substring.

It is a Curzon 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 7 ways as a sum of consecutive naturals, for example, 38660 + ... + 39189.

It is an arithmetic number, because the mean of its divisors is an integer number (3152925).

Almost surely, 2^20629985 is an apocalyptic number.

It is an amenable number.

20629985 is a deficient number, since it is larger than the sum of its proper divisors (4593415).

20629985 is an equidigital number, since it uses as much as digits as its factorization.

20629985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77907.

The product of its (nonzero) digits is 77760, while the sum is 41.

The square root of 20629985 is about 4542.0243284245. The cubic root of 20629985 is about 274.2624201939.

The spelling of 20629985 in words is "twenty million, six hundred twenty-nine thousand, nine hundred eighty-five".