771666642 has 32 divisors (see below), whose sum is σ = 1722202560. Its totient is φ = 256114080.

The previous prime is 771666641. The next prime is 771666647. The reversal of 771666642 is 246666177.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (771666641) 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 15 ways as a sum of consecutive naturals, for example, 18084 + ... + 43247.

It is an arithmetic number, because the mean of its divisors is an integer number (53818830).

Almost surely, 2^771666642 is an apocalyptic number.

771666642 is an abundant number, since it is smaller than the sum of its proper divisors (950535918).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

771666642 is a wasteful number, since it uses less digits than its factorization.

771666642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61575 (or 61569 counting only the distinct ones).

The product of its digits is 508032, while the sum is 45.

The square root of 771666642 is about 27778.8884226853. Note that the first 3 decimals coincide. The cubic root of 771666642 is about 917.2264618768.

The spelling of 771666642 in words is "seven hundred seventy-one million, six hundred sixty-six thousand, six hundred forty-two".