77531009 has 2 divisors, whose sum is σ = 77531010. Its totient is φ = 77531008.

The previous prime is 77530961. The next prime is 77531017. The reversal of 77531009 is 90013577.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57532225 + 19998784 = 7585^2 + 4472^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77531009 is a prime.

It is a super-2 number, since 2×77531009² = 12022114713116162, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (77531029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38765504 + 38765505.

It is an arithmetic number, because the mean of its divisors is an integer number (38765505).

Almost surely, 2^77531009 is an apocalyptic number.

It is an amenable number.

77531009 is a deficient number, since it is larger than the sum of its proper divisors (1).

77531009 is an equidigital number, since it uses as much as digits as its factorization.

77531009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6615, while the sum is 32.

The square root of 77531009 is about 8805.1694475461. The cubic root of 77531009 is about 426.4078048789.

The spelling of 77531009 in words is "seventy-seven million, five hundred thirty-one thousand, nine".