1980863640 has 256 divisors, whose sum is σ = 7675776000. Its totient is φ = 444994560.

The previous prime is 1980863609. The next prime is 1980863659. The reversal of 1980863640 is 463680891.

1980863640 is a `hidden beast` number, since 1 + 9 + 8 + 0 + 8 + 636 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 443820 + ... + 448260.

It is an arithmetic number, because the mean of its divisors is an integer number (29983500).

Almost surely, 2^1980863640 is an apocalyptic number.

1980863640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1980863640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3837888000).

1980863640 is an abundant number, since it is smaller than the sum of its proper divisors (5694912360).

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

1980863640 is a wasteful number, since it uses less digits than its factorization.

1980863640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4527 (or 4517 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The square root of 1980863640 is about 44506.8942974007. The cubic root of 1980863640 is about 1255.8897813271.

The spelling of 1980863640 in words is "one billion, nine hundred eighty million, eight hundred sixty-three thousand, six hundred forty".