1780720890 has 96 divisors (see below), whose sum is σ = 4706994240. Its totient is φ = 430829568.

The previous prime is 1780720873. The next prime is 1780720919. The reversal of 1780720890 is 980270871.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 296154 + ... + 302106.

It is an arithmetic number, because the mean of its divisors is an integer number (49031190).

Almost surely, 2^1780720890 is an apocalyptic number.

1780720890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1780720890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2353497120).

1780720890 is an abundant number, since it is smaller than the sum of its proper divisors (2926273350).

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

1780720890 is a wasteful number, since it uses less digits than its factorization.

1780720890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6048 (or 6035 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 42.

The square root of 1780720890 is about 42198.5887204774. The cubic root of 1780720890 is about 1212.0818587219.

The spelling of 1780720890 in words is "one billion, seven hundred eighty million, seven hundred twenty thousand, eight hundred ninety".