1639980 has 48 divisors (see below), whose sum is σ = 5103840. Its totient is φ = 437184.

The previous prime is 1639949. The next prime is 1639987. The reversal of 1639980 is 899361.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (1639987) 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, 979 + ... + 2058.

It is an arithmetic number, because the mean of its divisors is an integer number (106330).

2^1639980 is an apocalyptic number.

1639980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1639980 is an abundant number, since it is smaller than the sum of its proper divisors (3463860).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1639980 is a wasteful number, since it uses less digits than its factorization.

1639980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3055 (or 3047 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 1639980 is about 1280.6170387747. The cubic root of 1639980 is about 117.9268914179.

The spelling of 1639980 in words is "one million, six hundred thirty-nine thousand, nine hundred eighty".