1980556440 has 64 divisors (see below), whose sum is σ = 6291185760. Its totient is φ = 497080320.

The previous prime is 1980556399. The next prime is 1980556451. The reversal of 1980556440 is 446550891.

It is a junction number, because it is equal to n+sod(n) for n = 1980556392 and 1980556401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 483391 + ... + 487470.

Almost surely, 2^1980556440 is an apocalyptic number.

1980556440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1980556440 is an abundant number, since it is smaller than the sum of its proper divisors (4310629320).

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

1980556440 is a wasteful number, since it uses less digits than its factorization.

1980556440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 970892 (or 970888 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 42.

The square root of 1980556440 is about 44503.4430128726. The cubic root of 1980556440 is about 1255.8248552213.

It can be divided in two parts, 19805 and 56440, that added together give a triangular number (76245 = T₃₉₀).

The spelling of 1980556440 in words is "one billion, nine hundred eighty million, five hundred fifty-six thousand, four hundred forty".