77449681 has 4 divisors (see below), whose sum is σ = 81526000. Its totient is φ = 73373364.

The previous prime is 77449679. The next prime is 77449727. The reversal of 77449681 is 18694477.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18694477 = 467 ⋅40031.

It is not a de Polignac number, because 77449681 - 2¹ = 77449679 is a prime.

It is a super-2 number, since 2×77449681² = 11996906174003522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77449601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2038131 + ... + 2038168.

It is an arithmetic number, because the mean of its divisors is an integer number (20381500).

Almost surely, 2^77449681 is an apocalyptic number.

It is an amenable number.

77449681 is a deficient number, since it is larger than the sum of its proper divisors (4076319).

77449681 is a wasteful number, since it uses less digits than its factorization.

77449681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4076318.

The product of its digits is 338688, while the sum is 46.

The square root of 77449681 is about 8800.5500396282. The cubic root of 77449681 is about 426.2586558385.

The spelling of 77449681 in words is "seventy-seven million, four hundred forty-nine thousand, six hundred eighty-one".