77247997 has 2 divisors, whose sum is σ = 77247998. Its totient is φ = 77247996.

The previous prime is 77247979. The next prime is 77248033. The reversal of 77247997 is 79974277.

Together with previous prime (77247979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59151481 + 18096516 = 7691^2 + 4254^2 .

It is an emirp because it is prime and its reverse (79974277) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77247997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77247917) 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 as a sum of consecutive naturals, namely, 38623998 + 38623999.

It is an arithmetic number, because the mean of its divisors is an integer number (38623999).

Almost surely, 2^77247997 is an apocalyptic number.

It is an amenable number.

77247997 is a deficient number, since it is larger than the sum of its proper divisors (1).

77247997 is an equidigital number, since it uses as much as digits as its factorization.

77247997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1555848, while the sum is 52.

The square root of 77247997 is about 8789.0839681960. The cubic root of 77247997 is about 425.8883324612. Note that the first 3 decimals are identical.

The spelling of 77247997 in words is "seventy-seven million, two hundred forty-seven thousand, nine hundred ninety-seven".