77211891 has 12 divisors (see below), whose sum is σ = 115374480. Its totient is φ = 49699440.

The previous prime is 77211853. The next prime is 77211899. The reversal of 77211891 is 19811277.

It is not a de Polignac number, because 77211891 - 2¹³ = 77203699 is a prime.

It is a super-2 number, since 2×77211891² = 11923352223591762, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (77211899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 147655 + ... + 148176.

It is an arithmetic number, because the mean of its divisors is an integer number (9614540).

Almost surely, 2^77211891 is an apocalyptic number.

77211891 is a deficient number, since it is larger than the sum of its proper divisors (38162589).

77211891 is a wasteful number, since it uses less digits than its factorization.

77211891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295866 (or 295863 counting only the distinct ones).

The product of its digits is 7056, while the sum is 36.

The square root of 77211891 is about 8787.0297029201. The cubic root of 77211891 is about 425.8219681923.

The spelling of 77211891 in words is "seventy-seven million, two hundred eleven thousand, eight hundred ninety-one".