766761565421 has 8 divisors (see below), whose sum is σ = 771292114200. Its totient is φ = 762232148032.

The previous prime is 766761565369. The next prime is 766761565433. The reversal of 766761565421 is 124565167667.

It can be written as a sum of positive squares in 4 ways, for example, as 190847533321 + 575914032100 = 436861^2 + 758890^2 .

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 766761565421 - 2¹⁸ = 766761303277 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (766761565621) 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, 1096391 + ... + 1653963.

It is an arithmetic number, because the mean of its divisors is an integer number (96411514275).

Almost surely, 2^766761565421 is an apocalyptic number.

It is an amenable number.

766761565421 is a deficient number, since it is larger than the sum of its proper divisors (4530548779).

766761565421 is a wasteful number, since it uses less digits than its factorization.

766761565421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 565695.

The product of its digits is 12700800, while the sum is 56.

The spelling of 766761565421 in words is "seven hundred sixty-six billion, seven hundred sixty-one million, five hundred sixty-five thousand, four hundred twenty-one".