781243120 has 40 divisors (see below), whose sum is σ = 2075876064. Its totient is φ = 267854592.

The previous prime is 781243103. The next prime is 781243129. The reversal of 781243120 is 21342187.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×781243120² = 1220681625094668800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781243129) 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, 696979 + ... + 698098.

Almost surely, 2^781243120 is an apocalyptic number.

781243120 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

781243120 is an abundant number, since it is smaller than the sum of its proper divisors (1294632944).

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

781243120 is a wasteful number, since it uses less digits than its factorization.

781243120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1395097 (or 1395091 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 781243120 is about 27950.7266452949. The cubic root of 781243120 is about 921.0051710642.

The spelling of 781243120 in words is "seven hundred eighty-one million, two hundred forty-three thousand, one hundred twenty".