781040520 has 192 divisors, whose sum is σ = 2894739120. Its totient is φ = 180928512.

The previous prime is 781040479. The next prime is 781040527. The reversal of 781040520 is 25040187.

It can be written as a sum of positive squares in 8 ways, for example, as 566535204 + 214505316 = 23802^2 + 14646^2 .

It is a super-2 number, since 2×781040520² = 1220048587763740800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (781040527) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 74652 + ... + 84468.

Almost surely, 2^781040520 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 781040520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1447369560).

781040520 is an abundant number, since it is smaller than the sum of its proper divisors (2113698600).

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

781040520 is a wasteful number, since it uses less digits than its factorization.

781040520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9864 (or 9857 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 781040520 is about 27947.1021753598. The cubic root of 781040520 is about 920.9255493370.

The spelling of 781040520 in words is "seven hundred eighty-one million, forty thousand, five hundred twenty".