77630989 has 2 divisors, whose sum is σ = 77630990. Its totient is φ = 77630988.

The previous prime is 77630977. The next prime is 77631007. The reversal of 77630989 is 98903677.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56746089 + 20884900 = 7533^2 + 4570^2 .

It is an emirp because it is prime and its reverse (98903677) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77630989 - 2²¹ = 75533837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77630929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38815494 + 38815495.

It is an arithmetic number, because the mean of its divisors is an integer number (38815495).

Almost surely, 2^77630989 is an apocalyptic number.

It is an amenable number.

77630989 is a deficient number, since it is larger than the sum of its proper divisors (1).

77630989 is an equidigital number, since it uses as much as digits as its factorization.

77630989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 571536, while the sum is 49.

The square root of 77630989 is about 8810.8449651552. The cubic root of 77630989 is about 426.5910173361.

The spelling of 77630989 in words is "seventy-seven million, six hundred thirty thousand, nine hundred eighty-nine".