388861777 has 2 divisors, whose sum is σ = 388861778. Its totient is φ = 388861776.

The previous prime is 388861747. The next prime is 388861801. The reversal of 388861777 is 777168883.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 379626256 + 9235521 = 19484^2 + 3039^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-388861777 is a prime.

It is a super-2 number, since 2×388861777² = 302426963223195458, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (388861717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194430888 + 194430889.

It is an arithmetic number, because the mean of its divisors is an integer number (194430889).

Almost surely, 2^388861777 is an apocalyptic number.

It is an amenable number.

388861777 is a deficient number, since it is larger than the sum of its proper divisors (1).

388861777 is an equidigital number, since it uses as much as digits as its factorization.

388861777 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3161088, while the sum is 55.

The square root of 388861777 is about 19719.5785198366. The cubic root of 388861777 is about 729.9028938200.

The spelling of 388861777 in words is "three hundred eighty-eight million, eight hundred sixty-one thousand, seven hundred seventy-seven".