1980464640 has 640 divisors, whose sum is σ = 8400319488. Its totient is φ = 385351680.

The previous prime is 1980464587. The next prime is 1980464653. The reversal of 1980464640 is 464640891.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 1980464592 and 1980464601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 10053022 + ... + 10053218.

Almost surely, 2^1980464640 is an apocalyptic number.

1980464640 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 1980464640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4200159744).

1980464640 is an abundant number, since it is smaller than the sum of its proper divisors (6419854848).

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

1980464640 is a wasteful number, since it uses less digits than its factorization.

1980464640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258 (or 242 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 42.

The square root of 1980464640 is about 44502.4116200459. The cubic root of 1980464640 is about 1255.8054521720.

The spelling of 1980464640 in words is "one billion, nine hundred eighty million, four hundred sixty-four thousand, six hundred forty".