1978090240 has 144 divisors (see below), whose sum is σ = 5441389632. Its totient is φ = 674906112.

The previous prime is 1978090217. The next prime is 1978090291. The reversal of 1978090240 is 420908791.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 1978090193 and 1978090202.

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, 2481522 + ... + 2482318.

It is an arithmetic number, because the mean of its divisors is an integer number (37787428).

Almost surely, 2^1978090240 is an apocalyptic number.

1978090240 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 1978090240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2720694816).

1978090240 is an abundant number, since it is smaller than the sum of its proper divisors (3463299392).

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

1978090240 is an equidigital number, since it uses as much as digits as its factorization.

1978090240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1102 (or 1088 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 1978090240 is about 44475.7264134044. The cubic root of 1978090240 is about 1255.3033853286.

The spelling of 1978090240 in words is "one billion, nine hundred seventy-eight million, ninety thousand, two hundred forty".