766406021 has 16 divisors (see below), whose sum is σ = 826680960. Its totient is φ = 708341760.

The previous prime is 766406009. The next prime is 766406029. The reversal of 766406021 is 120604667.

It is a cyclic number.

It is not a de Polignac number, because 766406021 - 2¹⁸ = 766143877 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 (766406029) 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 15 ways as a sum of consecutive naturals, for example, 127925 + ... + 133781.

It is an arithmetic number, because the mean of its divisors is an integer number (51667560).

Almost surely, 2^766406021 is an apocalyptic number.

766406021 is a gapful number since it is divisible by the number (71) formed by its first and last digit.

It is an amenable number.

766406021 is a deficient number, since it is larger than the sum of its proper divisors (60274939).

766406021 is a wasteful number, since it uses less digits than its factorization.

766406021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6044.

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 766406021 is about 27684.0391019808. The cubic root of 766406021 is about 915.1373960318.

The spelling of 766406021 in words is "seven hundred sixty-six million, four hundred six thousand, twenty-one".