781161986491 has 8 divisors (see below), whose sum is σ = 789843472704. Its totient is φ = 772506072840.

The previous prime is 781161986483. The next prime is 781161986543. The reversal of 781161986491 is 194689161187.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 781161986491 - 2³ = 781161986483 is a prime.

It is a super-2 number, since 2×781161986491² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (781161986291) 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, 6331705 + ... + 6453898.

It is an arithmetic number, because the mean of its divisors is an integer number (98730434088).

Almost surely, 2^781161986491 is an apocalyptic number.

781161986491 is a deficient number, since it is larger than the sum of its proper divisors (8681486213).

781161986491 is a wasteful number, since it uses less digits than its factorization.

781161986491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12786281.

The product of its digits is 5225472, while the sum is 61.

The spelling of 781161986491 in words is "seven hundred eighty-one billion, one hundred sixty-one million, nine hundred eighty-six thousand, four hundred ninety-one".