775779840 has 240 divisors, whose sum is σ = 2931950736. Its totient is φ = 188006400.

The previous prime is 775779839. The next prime is 775779847. The reversal of 775779840 is 48977577.

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (775779847) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 251910 + ... + 254970.

Almost surely, 2^775779840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 775779840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1465975368).

775779840 is an abundant number, since it is smaller than the sum of its proper divisors (2156170896).

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

775779840 is a wasteful number, since it uses less digits than its factorization.

775779840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3101 (or 3082 counting only the distinct ones).

The product of its (nonzero) digits is 3457440, while the sum is 54.

The square root of 775779840 is about 27852.8246323420. The cubic root of 775779840 is about 918.8532656383.

The spelling of 775779840 in words is "seven hundred seventy-five million, seven hundred seventy-nine thousand, eight hundred forty".