77221811 has 2 divisors, whose sum is σ = 77221812. Its totient is φ = 77221810.

The previous prime is 77221763. The next prime is 77221841. The reversal of 77221811 is 11812277.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77221811 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (77221841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38610905 + 38610906.

It is an arithmetic number, because the mean of its divisors is an integer number (38610906).

Almost surely, 2^77221811 is an apocalyptic number.

77221811 is a deficient number, since it is larger than the sum of its proper divisors (1).

77221811 is an equidigital number, since it uses as much as digits as its factorization.

77221811 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1568, while the sum is 29.

The square root of 77221811 is about 8787.5941531229. The cubic root of 77221811 is about 425.8402036091.

The spelling of 77221811 in words is "seventy-seven million, two hundred twenty-one thousand, eight hundred eleven".