381919155721 has 2 divisors, whose sum is σ = 381919155722. Its totient is φ = 381919155720.

The previous prime is 381919155703. The next prime is 381919155727. The reversal of 381919155721 is 127551919183.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 368449000000 + 13470155721 = 607000^2 + 116061^2 .

It is a cyclic number.

It is not a de Polignac number, because 381919155721 - 2⁵ = 381919155689 is a prime.

It is not a weakly prime, because it can be changed into another prime (381919155727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190959577860 + 190959577861.

It is an arithmetic number, because the mean of its divisors is an integer number (190959577861).

Almost surely, 2^381919155721 is an apocalyptic number.

It is an amenable number.

381919155721 is a deficient number, since it is larger than the sum of its proper divisors (1).

381919155721 is an equidigital number, since it uses as much as digits as its factorization.

381919155721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 680400, while the sum is 52.

The spelling of 381919155721 in words is "three hundred eighty-one billion, nine hundred nineteen million, one hundred fifty-five thousand, seven hundred twenty-one".