781264660 has 48 divisors (see below), whose sum is σ = 1793010240. Its totient is φ = 283587840.

The previous prime is 781264643. The next prime is 781264661. The reversal of 781264660 is 66462187.

It is a super-2 number, since 2×781264660² = 1220748937929831200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781264661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 133312 + ... + 139048.

It is an arithmetic number, because the mean of its divisors is an integer number (37354380).

Almost surely, 2^781264660 is an apocalyptic number.

It is an amenable number.

781264660 is an abundant number, since it is smaller than the sum of its proper divisors (1011745580).

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

781264660 is a wasteful number, since it uses less digits than its factorization.

781264660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6376 (or 6374 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 40.

The square root of 781264660 is about 27951.1119635695. Note that the first 3 decimals coincide. The cubic root of 781264660 is about 921.0136354669.

The spelling of 781264660 in words is "seven hundred eighty-one million, two hundred sixty-four thousand, six hundred sixty".