766642421 has 4 divisors (see below), whose sum is σ = 811739052. Its totient is φ = 721545792.

The previous prime is 766642397. The next prime is 766642439. The reversal of 766642421 is 124246667.

766642421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 444619396 + 322023025 = 21086^2 + 17945^2 .

It is a cyclic number.

It is not a de Polignac number, because 766642421 - 2²² = 762448117 is a prime.

It is a super-3 number, since 3×766642421³ (a number of 28 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (766642441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22548290 + ... + 22548323.

It is an arithmetic number, because the mean of its divisors is an integer number (202934763).

Almost surely, 2^766642421 is an apocalyptic number.

It is an amenable number.

766642421 is a deficient number, since it is larger than the sum of its proper divisors (45096631).

766642421 is a wasteful number, since it uses less digits than its factorization.

766642421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45096630.

The product of its digits is 96768, while the sum is 38.

The square root of 766642421 is about 27688.3083809755. The cubic root of 766642421 is about 915.2314785568.

The spelling of 766642421 in words is "seven hundred sixty-six million, six hundred forty-two thousand, four hundred twenty-one".