20633985 has 12 divisors (see below), whose sum is σ = 35765652. Its totient is φ = 11004768.

The previous prime is 20633983. The next prime is 20634001. The reversal of 20633985 is 58933602.

It can be written as a sum of positive squares in 2 ways, for example, as 3069504 + 17564481 = 1752^2 + 4191^2 .

It is not a de Polignac number, because 20633985 - 2¹ = 20633983 is a prime.

It is a super-2 number, since 2×20633985² = 851522673960450, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (20633983) 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, 229222 + ... + 229311.

It is an arithmetic number, because the mean of its divisors is an integer number (2980471).

Almost surely, 2^20633985 is an apocalyptic number.

It is an amenable number.

20633985 is a deficient number, since it is larger than the sum of its proper divisors (15131667).

20633985 is a wasteful number, since it uses less digits than its factorization.

20633985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 458544 (or 458541 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 20633985 is about 4542.4646393781. The cubic root of 20633985 is about 274.2801448599.

It can be divided in two parts, 206 and 33985, that added together give a triangular number (34191 = T₂₆₁).

The spelling of 20633985 in words is "twenty million, six hundred thirty-three thousand, nine hundred eighty-five".