781949691 has 12 divisors (see below), whose sum is σ = 1130020320. Its totient is φ = 521051760.

The previous prime is 781949677. The next prime is 781949737. The reversal of 781949691 is 196949187.

It is not a de Polignac number, because 781949691 - 2¹⁷ = 781818619 is a prime.

It is a super-2 number, since 2×781949691² = 1222890638509990962, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (781945691) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 430 + ... + 39548.

It is an arithmetic number, because the mean of its divisors is an integer number (94168360).

Almost surely, 2^781949691 is an apocalyptic number.

781949691 is a deficient number, since it is larger than the sum of its proper divisors (348070629).

781949691 is a wasteful number, since it uses less digits than its factorization.

781949691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41346 (or 41343 counting only the distinct ones).

The product of its digits is 979776, while the sum is 54.

The square root of 781949691 is about 27963.3633706677. The cubic root of 781949691 is about 921.2827455441.

The spelling of 781949691 in words is "seven hundred eighty-one million, nine hundred forty-nine thousand, six hundred ninety-one".