1980649 has 6 divisors (see below), whose sum is σ = 2177210. Its totient is φ = 1800480.

The previous prime is 1980637. The next prime is 1980659. The reversal of 1980649 is 9460891.

It can be written as a sum of positive squares in only one way, i.e., 1545049 + 435600 = 1243^2 + 660^2 .

It is not a de Polignac number, because 1980649 - 2⁷ = 1980521 is a prime.

It is a super-2 number, since 2×1980649² = 7845940922402, which contains 22 as substring.

It is a Duffinian number.

1980649 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1980659) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8064 + ... + 8305.

2^1980649 is an apocalyptic number.

It is an amenable number.

1980649 is a deficient number, since it is larger than the sum of its proper divisors (196561).

1980649 is a wasteful number, since it uses less digits than its factorization.

1980649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16391 (or 16380 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 1980649 is about 1407.3553211609. The cubic root of 1980649 is about 125.5844418299.

The spelling of 1980649 in words is "one million, nine hundred eighty thousand, six hundred forty-nine".