77320181 has 4 divisors (see below), whose sum is σ = 80681952. Its totient is φ = 73958412.

The previous prime is 77320153. The next prime is 77320183. The reversal of 77320181 is 18102377.

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: 18102377 = 311 ⋅58207.

It is a cyclic number.

It is not a de Polignac number, because 77320181 - 2¹⁰ = 77319157 is a prime.

It is a super-2 number, since 2×77320181² = 11956820779745522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77320183) 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, 1680851 + ... + 1680896.

It is an arithmetic number, because the mean of its divisors is an integer number (20170488).

Almost surely, 2^77320181 is an apocalyptic number.

It is an amenable number.

77320181 is a deficient number, since it is larger than the sum of its proper divisors (3361771).

77320181 is a wasteful number, since it uses less digits than its factorization.

77320181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3361770.

The product of its (nonzero) digits is 2352, while the sum is 29.

The square root of 77320181 is about 8793.1894668544. The cubic root of 77320181 is about 426.0209475619.

The spelling of 77320181 in words is "seventy-seven million, three hundred twenty thousand, one hundred eighty-one".