1988649 has 24 divisors (see below), whose sum is σ = 3232320. Its totient is φ = 1168992.

The previous prime is 1988633. The next prime is 1988653. The reversal of 1988649 is 9468891.

It is not a de Polignac number, because 1988649 - 2⁴ = 1988633 is a prime.

1988649 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1988659) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2322 + ... + 3060.

It is an arithmetic number, because the mean of its divisors is an integer number (134680).

2^1988649 is an apocalyptic number.

It is an amenable number.

1988649 is a deficient number, since it is larger than the sum of its proper divisors (1243671).

1988649 is a wasteful number, since it uses less digits than its factorization.

1988649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 781 (or 778 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The square root of 1988649 is about 1410.1946674130. The cubic root of 1988649 is about 125.7532965684.

The spelling of 1988649 in words is "one million, nine hundred eighty-eight thousand, six hundred forty-nine".