782161661 has 8 divisors (see below), whose sum is σ = 786894264. Its totient is φ = 777441280.

The previous prime is 782161607. The next prime is 782161717. The reversal of 782161661 is 166161287.

It can be written as a sum of positive squares in 4 ways, for example, as 298425625 + 483736036 = 17275^2 + 21994^2 .

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 782161661 - 2²² = 777967357 is a prime.

It is a super-2 number, since 2×782161661² = 1223553727876557842, 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 (782161561) 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, 146735 + ... + 151971.

It is an arithmetic number, because the mean of its divisors is an integer number (98361783).

Almost surely, 2^782161661 is an apocalyptic number.

It is an amenable number.

782161661 is a deficient number, since it is larger than the sum of its proper divisors (4732603).

782161661 is a wasteful number, since it uses less digits than its factorization.

782161661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6111.

The product of its digits is 24192, while the sum is 38.

The square root of 782161661 is about 27967.1532516272. The cubic root of 782161661 is about 921.3659847698.

The spelling of 782161661 in words is "seven hundred eighty-two million, one hundred sixty-one thousand, six hundred sixty-one".