1780918656 has 96 divisors (see below), whose sum is σ = 5199847800. Its totient is φ = 539658240.

The previous prime is 1780918649. The next prime is 1780918661. The reversal of 1780918656 is 6568190871.

It is a tau number, because it is divible by the number of its divisors (96).

It is a junction number, because it is equal to n+sod(n) for n = 1780918599 and 1780918608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27300 + ... + 65628.

Almost surely, 2^1780918656 is an apocalyptic number.

1780918656 is a gapful number since it is divisible by the number (16) 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 1780918656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2599923900).

1780918656 is an abundant number, since it is smaller than the sum of its proper divisors (3418929144).

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

1780918656 is a wasteful number, since it uses less digits than its factorization.

1780918656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38368 (or 38345 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 51.

The square root of 1780918656 is about 42200.9319328377. The cubic root of 1780918656 is about 1212.1267281357.

The spelling of 1780918656 in words is "one billion, seven hundred eighty million, nine hundred eighteen thousand, six hundred fifty-six".