781001216 has 80 divisors (see below), whose sum is σ = 1684439064. Its totient is φ = 360382464.

The previous prime is 781001203. The next prime is 781001219. The reversal of 781001216 is 612100187.

It can be written as a sum of positive squares in 4 ways, for example, as 752953600 + 28047616 = 27440^2 + 5296^2 .

It is not an unprimeable number, because it can be changed into a prime (781001219) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 460466 + ... + 462158.

Almost surely, 2^781001216 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 781001216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (842219532).

781001216 is an abundant number, since it is smaller than the sum of its proper divisors (903437848).

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

781001216 is a wasteful number, since it uses less digits than its factorization.

781001216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1781 (or 1765 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 26.

The square root of 781001216 is about 27946.3989809063. The cubic root of 781001216 is about 920.9101012844.

The spelling of 781001216 in words is "seven hundred eighty-one million, one thousand, two hundred sixteen".