77409989 has 2 divisors, whose sum is σ = 77409990. Its totient is φ = 77409988.

The previous prime is 77409979. The next prime is 77410001. The reversal of 77409989 is 98990477.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66552964 + 10857025 = 8158^2 + 3295^2 .

It is an emirp because it is prime and its reverse (98990477) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77409989 - 2¹⁶ = 77344453 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 77409989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77409979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38704994 + 38704995.

It is an arithmetic number, because the mean of its divisors is an integer number (38704995).

Almost surely, 2^77409989 is an apocalyptic number.

It is an amenable number.

77409989 is a deficient number, since it is larger than the sum of its proper divisors (1).

77409989 is an equidigital number, since it uses as much as digits as its factorization.

77409989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1143072, while the sum is 53.

The square root of 77409989 is about 8798.2946643085. The cubic root of 77409989 is about 426.1858259726.

The spelling of 77409989 in words is "seventy-seven million, four hundred nine thousand, nine hundred eighty-nine".