77281893 has 12 divisors (see below), whose sum is σ = 120216460. Its totient is φ = 47558016.

The previous prime is 77281889. The next prime is 77281901. The reversal of 77281893 is 39818277.

It can be written as a sum of positive squares in 2 ways, for example, as 17791524 + 59490369 = 4218^2 + 7713^2 .

It is not a de Polignac number, because 77281893 - 2² = 77281889 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77281823) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 330148 + ... + 330381.

Almost surely, 2^77281893 is an apocalyptic number.

It is an amenable number.

77281893 is a deficient number, since it is larger than the sum of its proper divisors (42934567).

77281893 is a wasteful number, since it uses less digits than its factorization.

77281893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 660548 (or 660545 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 77281893 is about 8791.0120577781. The cubic root of 77281893 is about 425.9506158451.

The spelling of 77281893 in words is "seventy-seven million, two hundred eighty-one thousand, eight hundred ninety-three".