761997661 has 4 divisors (see below), whose sum is σ = 762082272. Its totient is φ = 761913052.

The previous prime is 761997653. The next prime is 761997713. The reversal of 761997661 is 166799167.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 761997661 - 2³ = 761997653 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 761997599 and 761997608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (761997601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26935 + ... + 47428.

It is an arithmetic number, because the mean of its divisors is an integer number (190520568).

It is a 9006-hyperperfect number.

Almost surely, 2^761997661 is an apocalyptic number.

It is an amenable number.

761997661 is a deficient number, since it is larger than the sum of its proper divisors (84611).

761997661 is a wasteful number, since it uses less digits than its factorization.

761997661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84610.

The product of its digits is 857304, while the sum is 52.

The square root of 761997661 is about 27604.3051171371. The cubic root of 761997661 is about 913.3794005778.

The spelling of 761997661 in words is "seven hundred sixty-one million, nine hundred ninety-seven thousand, six hundred sixty-one".