20969985 has 8 divisors (see below), whose sum is σ = 33552000. Its totient is φ = 11183984.

The previous prime is 20969953. The next prime is 20969989. The reversal of 20969985 is 58996902.

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 20969985 - 2⁵ = 20969953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20969989) 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, 698985 + ... + 699014.

It is an arithmetic number, because the mean of its divisors is an integer number (4194000).

Almost surely, 2^20969985 is an apocalyptic number.

It is an amenable number.

20969985 is a deficient number, since it is larger than the sum of its proper divisors (12582015).

20969985 is a wasteful number, since it uses less digits than its factorization.

20969985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1398007.

The product of its (nonzero) digits is 349920, while the sum is 48.

The square root of 20969985 is about 4579.2996189374. The cubic root of 20969985 is about 275.7609119347.

The spelling of 20969985 in words is "twenty million, nine hundred sixty-nine thousand, nine hundred eighty-five".