781040957 has 4 divisors (see below), whose sum is σ = 781882620. Its totient is φ = 780199296.

The previous prime is 781040951. The next prime is 781040977. The reversal of 781040957 is 759040187.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 146555236 + 634485721 = 12106^2 + 25189^2 .

It is a cyclic number.

It is not a de Polignac number, because 781040957 - 2¹⁰ = 781039933 is a prime.

It is a super-2 number, since 2×781040957² = 1220049953022951698, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781040951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 419438 + ... + 421295.

It is an arithmetic number, because the mean of its divisors is an integer number (195470655).

Almost surely, 2^781040957 is an apocalyptic number.

It is an amenable number.

781040957 is a deficient number, since it is larger than the sum of its proper divisors (841663).

781040957 is an equidigital number, since it uses as much as digits as its factorization.

781040957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 841662.

The product of its (nonzero) digits is 70560, while the sum is 41.

The square root of 781040957 is about 27947.1099937006. The cubic root of 781040957 is about 920.9257210926.

The spelling of 781040957 in words is "seven hundred eighty-one million, forty thousand, nine hundred fifty-seven".