767680021 has 2 divisors, whose sum is σ = 767680022. Its totient is φ = 767680020.

The previous prime is 767680007. The next prime is 767680049. The reversal of 767680021 is 120086767.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 722856996 + 44823025 = 26886^2 + 6695^2 .

It is a cyclic number.

It is not a de Polignac number, because 767680021 - 2⁹ = 767679509 is a prime.

It is a super-2 number, since 2×767680021² = 1178665229285120882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (767680421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 383840010 + 383840011.

It is an arithmetic number, because the mean of its divisors is an integer number (383840011).

Almost surely, 2^767680021 is an apocalyptic number.

It is an amenable number.

767680021 is a deficient number, since it is larger than the sum of its proper divisors (1).

767680021 is an equidigital number, since it uses as much as digits as its factorization.

767680021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 767680021 is about 27707.0391958434. The cubic root of 767680021 is about 915.6441942510.

The spelling of 767680021 in words is "seven hundred sixty-seven million, six hundred eighty thousand, twenty-one".