77738981 has 2 divisors, whose sum is σ = 77738982. Its totient is φ = 77738980.

The previous prime is 77738963. The next prime is 77739007. The reversal of 77738981 is 18983777.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59752900 + 17986081 = 7730^2 + 4241^2 .

It is a cyclic number.

It is not a de Polignac number, because 77738981 - 2²² = 73544677 is a prime.

It is a super-2 number, since 2×77738981² = 12086698333836722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77738951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38869490 + 38869491.

It is an arithmetic number, because the mean of its divisors is an integer number (38869491).

Almost surely, 2^77738981 is an apocalyptic number.

It is an amenable number.

77738981 is a deficient number, since it is larger than the sum of its proper divisors (1).

77738981 is an equidigital number, since it uses as much as digits as its factorization.

77738981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 592704, while the sum is 50.

The square root of 77738981 is about 8816.9711919684. The cubic root of 77738981 is about 426.7887350791.

The spelling of 77738981 in words is "seventy-seven million, seven hundred thirty-eight thousand, nine hundred eighty-one".