77021291 has 2 divisors, whose sum is σ = 77021292. Its totient is φ = 77021290.

The previous prime is 77021279. The next prime is 77021293. The reversal of 77021291 is 19212077.

It is a strong prime.

It is an emirp because it is prime and its reverse (19212077) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77021291 - 2²² = 72826987 is a prime.

It is a Sophie Germain prime.

Together with 77021293, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (77021293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38510645 + 38510646.

It is an arithmetic number, because the mean of its divisors is an integer number (38510646).

Almost surely, 2^77021291 is an apocalyptic number.

77021291 is a deficient number, since it is larger than the sum of its proper divisors (1).

77021291 is an equidigital number, since it uses as much as digits as its factorization.

77021291 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1764, while the sum is 29.

The square root of 77021291 is about 8776.1774708583. The cubic root of 77021291 is about 425.4712944761.

The spelling of 77021291 in words is "seventy-seven million, twenty-one thousand, two hundred ninety-one".