781608961 has 16 divisors (see below), whose sum is σ = 902356864. Its totient is φ = 663168384.

The previous prime is 781608943. The next prime is 781609009. The reversal of 781608961 is 169806187.

It is a cyclic number.

It is not a de Polignac number, because 781608961 - 2¹¹ = 781606913 is a prime.

It is a super-2 number, since 2×781608961² = 1221825135830999042, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (781600961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 314821 + ... + 317293.

It is an arithmetic number, because the mean of its divisors is an integer number (56397304).

Almost surely, 2^781608961 is an apocalyptic number.

It is an amenable number.

781608961 is a deficient number, since it is larger than the sum of its proper divisors (120747903).

781608961 is a wasteful number, since it uses less digits than its factorization.

781608961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2920.

The product of its (nonzero) digits is 145152, while the sum is 46.

The square root of 781608961 is about 27957.2702708973. The cubic root of 781608961 is about 921.1489115822.

The spelling of 781608961 in words is "seven hundred eighty-one million, six hundred eight thousand, nine hundred sixty-one".