77651261 has 2 divisors, whose sum is σ = 77651262. Its totient is φ = 77651260.

The previous prime is 77651251. The next prime is 77651269. The reversal of 77651261 is 16215677.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77545636 + 105625 = 8806^2 + 325^2 .

It is an emirp because it is prime and its reverse (16215677) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77651261 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77651269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38825630 + 38825631.

It is an arithmetic number, because the mean of its divisors is an integer number (38825631).

Almost surely, 2^77651261 is an apocalyptic number.

It is an amenable number.

77651261 is a deficient number, since it is larger than the sum of its proper divisors (1).

77651261 is an equidigital number, since it uses as much as digits as its factorization.

77651261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17640, while the sum is 35.

The square root of 77651261 is about 8811.9952905117. The cubic root of 77651261 is about 426.6281464112.

The spelling of 77651261 in words is "seventy-seven million, six hundred fifty-one thousand, two hundred sixty-one".