19864985 has 16 divisors (see below), whose sum is σ = 28429056. Its totient is φ = 13028928.

The previous prime is 19864981. The next prime is 19864987. The reversal of 19864985 is 58946891.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 19864985 - 2² = 19864981 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19864981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11534 + ... + 13143.

It is an arithmetic number, because the mean of its divisors is an integer number (1776816).

Almost surely, 2^19864985 is an apocalyptic number.

It is an amenable number.

19864985 is a deficient number, since it is larger than the sum of its proper divisors (8564071).

19864985 is a wasteful number, since it uses less digits than its factorization.

19864985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24712.

The product of its digits is 622080, while the sum is 50.

The square root of 19864985 is about 4457.0152568731. The cubic root of 19864985 is about 270.8295701778.

The spelling of 19864985 in words is "nineteen million, eight hundred sixty-four thousand, nine hundred eighty-five".